Tel Aviv - For nearly 40 years, everything about Gil Grunbaum's life was a lie, including his name.

He was not, as he had always assumed, the only son of wealthy Holocaust survivors who owned a baby garments factory near Tel Aviv. Grunbaum had been stolen from his mother by doctors at a hospital in northern Israel in 1956, moments after she gave birth.

His biological parents - recent immigrants to Israel from Tunisia - were told their child had died during delivery. They were sent home without a death certificate and denied the chance to see their baby's body or a grave.

Despite his darker looks, it never occurred to Grunbaum that the parents who raised him were not biologically related to him. Now aged 60, he says the discovery was "the most shocking moment imaginable. Everyone I loved - my parents, aunts, uncles and cousins - had been deceiving me for decades."

And so had government officials.

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"Even when I discovered by chance that I was adopted, the welfare services did everything they could to try to stop me finding my biological family," Grunbaum told Al Jazeera. "No one wanted me to know the truth."

After a three-year search in the late 1990s, he finally learned his family's name - Maimon - and tracked down his birth mother to the suburbs of Haifa in northern Israel. Some 41 years after they were separated, the two met for the first time, in an emotional reunion.

Grunbaum's story would be deeply disturbing if it was unique. But growing evidence suggests that there could be thousands of other children who were abducted in Israel's first decade.

Last weekend, Tzachi Hanegbi, a government minister tasked with studying the disappearances, conceded that at least "hundreds" of children had been taken without their parents' consent. It is the first time a government official has ever made such a public admission.

After weeks of re-examining evidence presented to a commission of inquiry in the late 1990s, Hanegbi told Israeli TV: "They took the children and gave them away. I don't know where."

The Kedmi inquiry, which had issued its findings in 2001, found that as many as 5,000 children may have disappeared in the state's first six years alone, although it examined only 1,000 of those cases. Jacob Kedmi, a former Supreme Court judge who died last month, concluded that in most cases, the children had died and been hurriedly buried.

Hanegbi's admission appears to confirm allegations long made by the families - and supported by scholars and journalists - that the inquiry was little more than a whitewash by the Israeli establishment. Kedmi placed the hundreds of thousands of documents relating to testimonies and evidence under lock for 70 years. They will not be made publicly available until 2071.

This was a crime perpetrated against thousands of parents, who still don't know the truth about their children's fate. Shoshana Madmoni-Gerber, author of Israeli Media and the Framing of Internal Conflict: The Yemenite Babies Affair

The first consequence is likely to be mounting pressure on the government to open the state's adoption files so that the true extent of the disappearances can be gauged and families reunited.

But Hanegbi's otherwise evasive comments will do little to end suspicions that officials are still actively trying to avoid confronting the most contentious questions: Why were the infants taken from their families? Did hospitals and welfare organisations traffic children in Israel's early years? And were state bodies complicit in the mass abductions?

When asked by Israeli TV programme Meet the Press whether government officials were involved, Hanegbi would say only: "We may never know."

His reluctance to be more forthcoming may be understandable. Shoshana Madmoni-Gerber, an Israel academic who has written a book on the disappearances titled Israeli Media and the Framing of Internal Conflict: The Yemenite Babies Affair, noted that the "forcible transfer" of children from one ethnic group to another satisfied the United Nations definition of "genocide". The 1951 convention includes the crime of "complicity".

"Ultimately, I don't think it matters whether government officials actively planned what happened or they simply looked the other way while others carried out the kidnappings," she told Al Jazeera. "Either way, this was a crime perpetrated against thousands of parents who still don't know the truth about their children's fate."

Almost all of the missing children were from Jewish families that had arrived from Arab countries shortly after Israel's creation during the Nakba of 1948, when hundreds of thousands of native Palestinians were expelled from their homes.

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The mystery has been dubbed the Yemenite Children Affair, because most of the children who disappeared were from Yemen. But there were also significant numbers from Iraq, Morocco, Tunisia and the Balkans.

Grunbaum learned of his own place in this scandalous affair in 1994, the year before the Kedmi inquiry was launched. His wife had become suspicious that there were no photos of his birth or a birth certificate, and that he was much darker than his parents.

When she phoned state childcare services, a clerk broke Israel's strict privacy laws by mistakenly revealing to her that Grunbaum had indeed been adopted. The couple was then hastily called to a meeting at the Tel Aviv office, where they were briefly allowed to view two pages from his file. No details of his biological family were provided.

"Even in my confused state, I could see there was something fishy. There was no signature on the adoption papers, either from my biological mother or from a judge," Grunbaum said.

"I was in a state of shock for a long time afterwards. I stared at the TV all day long for four months, running my life through my head, looking for the clues I should have seen. I resigned from my job. I couldn't concentrate on anything else."

Although childcare services had details of his biological family, they refused to help. It took three years of intensive searching - initiated by the recollections of neighbours of his parents at the time of his adoption - before he was sure he had identified the family.

"I went straight to the head of child services and told her their surname. I asked her if I was right - I didn't need a reply," Grunbaum said, noting the colour drained from the woman's face as she realised he had found his biological family.

Grunbaum's biological father had died a few years earlier, but he met his biological mother in a supervised visit in Haifa. It had taken her a month to recover sufficiently from hearing the news that her son was alive to agree to a meeting.

"She hugged me and we cried. I gave her an album of photos of my three children. She said with surprise, 'I have a blond grandson!'"

Grunbaum then started a double life, visiting his biological mother and his five siblings while hiding the truth from his adoptive parents until their deaths a few years later. "I was afraid to confront them. They were elderly and in poor health. I think it would have destroyed them to realise I knew the truth."

The irregularities in the adoption papers indicate that his parents were likely to have known their adopted child was procured without the biological mother's consent. Grunbaum admits he was filled with confusion and anger at his parents for a long time. Shortly after he found out about the circumstances of his adoption, his parents celebrated their 50th wedding anniversary.

"They asked me to make a speech at the party, but I couldn't. I was too frightened of what might come out of my mouth," he said.

Pressure on the Israeli government to provide answers in cases like Grunbaum's has intensified in recent years, as social media has helped the affected families to understand how widespread the disappearances were.

In late June, Prime Minister Benjamin Netanyahu responded by announcing a fresh examination of the evidence. In a video posted to his Facebook page, he promised to get to the bottom of the affair: "The subject of the Yemenite children is an open wound that continues to bleed for many families who don't know what happened to the infants, to the children who disappeared."

He appointed Hanegbi to re-examine the documents from three previous inquiries.

Yael Tzadok, an Israeli journalist who has spent 20 years investigating cases of children who disappeared, told Al Jazeera: "This is Israel's darkest secret. Jews kidnapped other Jews, Jews who were coming to a state that had been created as a refuge in the immediate wake of the Holocaust. Bringing the truth into the daylight risks causing an earthquake."

The families and their supporters believe the majority of the children are still alive, but only a minuscule number, like Grunbaum, know that they were stolen from their parents.

Even among those few, said Madmoni-Gerber, most are reluctant to go public, fearing that the truth will tear apart their families, who may have conspired in their abduction.

Israeli Jews who originate from Arab countries are known in Israel as Mizrahim, in contrast to those of European heritage, who are called Ashkenazim. Tzadok said the evidence suggested that most of the missing children - from Mizrahi families - were taken by hospital staff and sold or given away to European Jews, both in Israel and abroad.

"The evidence from that time, the 1950s, clearly shows government officials, judges, lawmakers and hospital staff speaking openly about the fact that the children were being abducted. The public may not have known, but the authorities certainly did," Tzadok said.

Tzadok, who is active with Achim Vekayamim, a forum for the families of missing children, said deep prejudices among European Jews against the Mizrahim - and especially the Yemenites - had made the kidnappings possible.

"Mizrahi parents were seen as bad, primitive people who were a lost cause. The dominant view then was that, by placing the children with Ashkenazi families, they could be saved - unlike their parents. They would be re-educated and made into suitable material for the new Zionist state," Tzadok said.

"The hospital staff and officials probably didn't think they were doing something wrong. They thought it was their patriotic duty."

Racism among European Jews towards Jews from Arab countries reached the very top of the government. Ben Gurion, Israel's first prime minister, described the Mizrahim as "rabble" and a "generation of the desert", concluding that they lacked "a trace of Jewish or human education".

In the early 1950s, he warned: "We do not want the Israelis to become Arabs. It is incumbent upon us to struggle against the spirit of the Levant, which corrupts individuals and societies."

Recently unearthed documents also show vigorous debates within the Israeli army in the early 1950s about whether Mizrahi conscripts were mentally retarded, making them a hopeless cause, or simply primitive, a condition that could be changed.

In his book The Idea of Israel, historian Ilan Pappe observed that Israel's Ashkenazi elite worked strenuously at "de-Arabising … Jews upon arrival" in Israel.

The establishment's open disdain for the Mizrahim eventually led to political backlash, noted Pappe. In the late 1970s, after decades in opposition, the right-wing Likud party won power from Ben Gurion's Labour party. Today, Likud is led by Netanyahu.

Grunbaum said Israel's European elite were also sympathetic to the plight of Holocaust survivors, like his adoptive parents, who had lost most or all of their family and struggled to have children of their own.

The nurse said, 'You have lots of children, why not let us take one of them?' My grandmother refused. A couple of days later, the nurse told her her baby girl had died. She did not receive a death certificate and was not shown a grave. Shlomi Hatuka, who helped found Amram, an organisation campaigning on behalf of the families

"My father had been in Auschwitz and my mother in Dachau. The survivors suffered from psychological and physical traumas that meant it was difficult or impossible for them to have children," he said. "The view at that time was that the Yemenites had large families and could afford to lose one or two."

The Kedmi inquiry heard such views expressed by medical staff who worked in hospitals suspected of abducting children. Sonia Milshtein, a former senior nurse, testified that Yemenite parents "were not interested in their children" and that they should have been happy that their "child got a good education".

Sarah Pearl, head nurse at the Women's International Zionist Organisation (WIZO), a charity that ran care homes from which children are alleged to have disappeared, told Israeli media that when she asked why the children's parents never visited, she was told by the head administrator that they "have lots of kids, and lots of problems, so they don't want their children".

Like many of those who have been campaigning for greater transparency, Madmoni-Gerber, an Israeli professor of communications now based in the United States, said her own family had been scarred by the Yemenite Children Affair.

Her father and aunt were among 50,000 Yemenite Jews airlifted to Israel in 1949 and 1950 in a series of secret US and British flights known as Operation Magic Carpet. Like many other Mizrahim, they were temporarily sheltered in one of dozens of "absorption camps" across Israel.

Madmoni-Gerber's aunt gave birth in an Israeli hospital in 1949. "When it was time to go home, staff on the delivery ward asked her to leave her baby behind with them. She refused. When she arrived back at the camp, the child was snatched [by staff] out of her hands. She never saw her baby again."

Hanegbi's admission is certain to rock an Ashkenazi establishment that has long been in denial about the Yemenite Children Affair.

For instance, Yaron London, one of Israel's best-known commentators, has called suggestions of kidnappings a "conspiracy theory".

And Dov Levitan, a professor at Bar Ilan University, near Tel Aviv, who is a leading expert on Yemenite immigration to Israel, recently stated: "I can't put even one finger on a case in which I can say that there was an act of abduction or a criminal act."

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Shlomi Hatuka, a 38-year-old Yemenite poet and teacher who three years ago helped found Amram, an organisation campaigning on behalf of the families, said that continuing racism towards the Mizrahim had made possible a "conspiracy of silence" lasting more than six decades.

His activism began after his grandmother revealed to him 22 years ago that she had been asked by a nurse in the early 1950s to give up for adoption one of the twins she had just given birth to.

"The nurse said, 'You have lots of children, why not let us take one of them?'" Hatuka told Al Jazeera. "My grandmother refused. A couple of days later, the nurse told her her baby girl had died. She did not receive a death certificate and was not shown a grave.

"My mother told me my grandmother talked about her kidnapped child until the day she died," he added. "She never got over it. At the time, none of us could really grasp what had happened to [the baby]. It was just too strange. It was impossible to believe."

Hatuka said the official re-examination of the files had been prompted by growing pressure from the Mizrahi community: "We are the third generation, and we are better able to organise. We have used social media and new technology to help bring more attention to the kidnappings."

Amram is demanding that the Israeli authorities open up adoption papers so that the children who were abducted can try to find their parents. "If Netanyahu really wants to help clarify what happened, this would be the easiest and quickest way to do it," Hatuka said.

Currently, a 1960 Adoption Law makes it a criminal offence for an adopted child or their adoptive parents to publicly reveal that an adoption took place. Officials have claimed the restriction is needed to protect privacy, but there is mounting pressure to scrap it.

Amram has also established a database of missing children on its website. Hundreds more families have come forward with information of children who disappeared, including cases that have never been investigated. Hatuka believes that the total number of children who are missing could be as high as 8,000.

Even based on the official figures, one in eight Yemenite infants under the age of four may have disappeared in the state's first six years. Boaz Sangero, a law professor at a college near Tel Aviv, wrote in the Haaretz newspaper this month that the figure was "astonishing", and demanded an urgent re-examination of the evidence.

The extent of the problem was further underscored last month when four legislators in the 120-seat Israeli parliament came forward to reveal that their own relatives had disappeared in the 1950s. Two were from Netanyahu's Likud party.

Nurit Koren, whose cousin went missing, told The Jerusalem Post newspaper: "Everybody is coming and telling me it happened in their families too. The phone doesn't stop ringing."

Nava Boker said that her sister and brother were taken. "I am afraid that the same people who planned and executed these crimes of ripping babies away from their mothers' arms ensured their own safety and hid the documents." Boker and other activists have been infuriated by the Kedmi inquiry's decision to place under lock hundreds of thousands of documents relating to its investigations until 2071.

There has also been widespread criticism of the way the inquiry was conducted. Tzadok called the panel's report "shameful", and accused it of ignoring the evidence of wrongdoing it unearthed.

Sangero noted that the commission employed only two investigators to look into the case files of some 1,000 missing children. In 69 cases, it said it could not determine the children's fate.

The panel avoided using its subpoena powers, thereby allowing officials to refuse to testify, or agreed to let them give evidence behind closed doors. The inquiry also did not carry out DNA tests.

On many occasions, birth and burial records requested by the Kedmi inquiry either disappeared or were reported to have been destroyed by fires or floods. The inquiry, Sangero observed, did not investigate how so many files could have been lost.

The panel was equally trusting of a 1960 census that listed many of the supposedly dead children as having "left the country". In addition, the inquiry failed to examine why many of the biological parents received military draft notices for their children on what would have been their 18th birthdays.

Tzadok noted that, in one of the most disturbing oversights, the inquiry failed to probe the disappearance of 40 infants after they were supposedly sent from an absorption camp to Jerusalem for immunisations.

On its website, Amram has compiled damning testimonies presented to the three inquiries that suggest abductions of Mizrahi children were widespread and systematic, and might have amounted to trafficking. Such evidence appears to have swayed Hanegbi too. He told Meet the Press: "I'm reading testimony of nurses, social workers and people who admitted the children to hospitals and a variety of people, each of whom saw a small piece of the puzzle."

Ahuva Goldfarb, national supervisor of social services at that time, admitted to the Kedmi inquiry that children had been "unregistered" when sent out of the absorption camps, away from their parents.

He added: "It was systematic as could be." The parents were told their child was "no longer alive".

In a letter dated April 1950, a senior health ministry official, Dr M Lichtig, expressed concern to state hospitals that children were not being returned to their parents.

"There have been instances in which children were released from hospital and did not return to their parents. Apparently, they were found by people seeking to adopt," he wrote in the letter. "The bereaved parents searched for their children … We must make every effort to ensure that such incidents do not repeat themselves."

Hanna Gibori, head of adoption services in the country's north at that time, testified: "Hospital physicians handed over babies for adoption straight out of the hospital, without the official adoption agencies being involved."

As late as 1959, a Knesset member, Ben-Zion Harel, said a significant number of children were being placed for adoption at Israeli hospitals in "unacceptable ways", bordering on "trafficking".

All of this appears to have occurred with minimal or non-existent judicial oversight. In 1955, a high court judge, Shneur Cheshin, wrote in a decision: "To our embarrassment, fictitious adoption orders and custodial orders are issued weekly, indeed daily."

Hospitals and government officials were able to take advantage of the absence throughout the 1950s of any adoption laws. Oversight was only tightened up in 1960, with the passage of the Adoption Law.

A nurse who had once worked at the Batar hospital in Haifa, where Grunbaum was born in 1956, admitted on an Israeli TV show that prospective parents would "place an order" for children with the hospital. Batar closed in 1976, but requests by the Kedmi inquiry to see its archives were met with claims that the documents were either lost or destroyed by fire.

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Grunbaum's story, though rare, is not unique. Investigations over the past two decades have unearthed a handful of similar cases.

After Amram launched its website, a friend of the family revealed to Hatuka that she had been in an institution where she believed Yemenite children like herself were trafficked.

Hatuka has been able to piece together the early life of the woman, who agreed to be identified by the pseudonym Shoshana. She and her twin brother were taken from their mother at birth and placed in a care home in Jerusalem run by WIZO.

WIZO, which still runs childcare services in Israel, is mentioned in several cases of missing children who were later found. In a statement to Al Jazeera, WIZO said that the process of admitting and releasing children from the institutions it ran was managed by authorised government authorities, noting: "WIZO's sole responsibility was to care for the health and wellbeing of the children. Throughout the years, WIZO has provided authorities, upon request, with all of the records and materials relevant to the children in its institutions. WIZO fully supports any investigation that could shed light on issues subject to public debate."

At seven, Shoshana and her brother were moved to an ultra-Orthodox institution for parentless Yemenite children called Gur Aryeh, in Bnei Brak, near Tel Aviv. Shoshana told Hatuka that intermittently they would be gathered in a room and visitors, called "American aunts", would inspect them. Children would regularly disappear.

During her stay in Gur Aryeh, Shoshana was told that her biological mother had died five years after giving birth to her.

In the late 1990s, when the Kedmi inquiry was under way, a few Israeli journalists intensified their search for such children.

In the most famous case, widely reported in 1997, Tzila Levine was reunited with her biological mother after a 20-year search. DNA testing confirmed her blood ties to Margalit Umaysi, an immigrant from Yemen.

It is time for the country to be more open about its past. We need to drag these issues into the sunlight and see what really happened. Gil Grunbaum, adopted as a baby

A doctor in Haifa had taken Levine from Umaysi shortly after her birth in 1949 and handed her to adoptive parents using forged papers. The adoption was approved by Moshe Landau, a judge who went on to serve in Israel's Supreme Court.

''I feel that I've won a war - a lifelong war," Levine told reporters at the time.

The case of Tziona Heiman was exposed five years later by the Yedioth Ahronoth newspaper. After she confronted her Ashkenazi parents with suspicions that she was adopted, they admitted that she had been selected from a Jerusalem hospital.

Their neighbour, Yigal Allon, a famous Israeli general, had - in their words - given them the girl as a "birthday present". Heiman later found her biological parents.

Madmoni-Gerber also located an abducted child in 1994, when she was an Israeli journalist. Moshe Becher was taken from his Yemenite family in 1953 and placed in the care of WIZO. A Turkish couple were issued a forged birth certificate for him in 1956.

Like most, Becher was never shown his adoption file, and was unable to track down his biological parents. A letter from the welfare services stated simply: "We have no clue as to your mother's identity or whereabouts."

Hatuka said Amram was now working to create a private DNA database abroad. It would allow both those who suspected they were kidnapped - including those now living in Europe or the US - and the parents of missing children to submit their DNA to see if matches could be made.

Grunbaum said the families' campaign was not a quest for revenge against those behind the kidnappings.

"It is time for the country to be more open about its past," he said. "We need to drag these issues into the sunlight and see what really happened."