The case of a young couple in Norway whose five children were taken away by the state has fuelled mounting concern within the country and abroad over its child protection practices. Protesters around the world - and leading Norwegian professionals - say social workers are often too quick to separate children from their families, with too little justification, particularly when parents are immigrants.

Ruth and Marius's life was torn apart without warning one Monday afternoon last November when two black cars approached the farm where they live in a remote Norwegian valley.

Their two little boys, aged five and two, and their three-month-old baby son, were in their big, bright, modern living room overlooking the steel-grey fjord.

Ruth was waiting as usual for the school bus that would bring back their two daughters, aged eight and 10.

But that Monday, it never came. Instead, Ruth saw the two unknown cars. One continued along the main road; the other turned up the farm track - and a woman from the local child protection service knocked at the door.

She told Ruth to come to the police station for interrogation.

The woman said the other black car had taken Ruth's two daughters away, into emergency state care. And she told Ruth to hand over her two older sons to be taken away, too.

The following day, two black cars appeared again. The couple assumed it had all been a terrible mistake and the children had been brought back.

But they were wrong. Four policemen got out. And took the baby.

Media playback is unsupported on your device Media caption Ruth and Marius describe how their children were taken away over the course of two days

Those events have triggered a worldwide protest campaign, online and on the streets.

Thousands of people have joined demonstrations in support of Ruth and Marius in a series of countries across four continents. The Norwegian child protection service, known as Barnevernet, has been accused by protesters of "kidnapping" children - in this and many other cases.

But Ruth and Marius's story isn't as simple as some campaigners imply.

They were suspected of administering corporal punishment, and in Norway, that's completely illegal.

Sitting in their living room, surrounded by long-unused toys, Ruth, a paediatric nurse, whose family has lived in the valley for generations, and Marius, a computer expert originally from Romania, are close to tears as they talk about what happened.

Ruth says they did spank the children. But she adds: "Not every time when they do something bad, more occasionally."

"They didn't find any physical marks or anything like that when they had medical examination on them, they were, are, all fine," she says. "But the law in Norway, it is very clear until the smallest detail, it's not allowed of any physical correction, and we have never been aware that it was this strict."

Norway: Parents against the state

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A lawyer for the couple wouldn't let me ask Ruth and Marius more detailed questions, because they're still under investigation.

And it's impossible to find out the authorities' side of the story, because the child protection service won't discuss individual cases, to protect children's privacy.

There is a lack of what I'd call the human factor… It's more like police interventions Einar Salvesen, Psychologist

But the couple's supporters are concerned not just about the initial removal of the children - but about what happened afterwards.

The children were split between three different sets of emergency foster parents. Marius and Ruth had an eight-hour round trip to get to supervised meetings with the baby, and separately with the two older boys.

The couple say Barnevernet initially told them there would be a meeting immediately after the children were taken, to discuss under what conditions the family might be reunited. But they say the meeting that eventually took place, much later, had a completely different agenda.

"By then we had already engaged ourselves in family counselling, to be prepared to fix whatever needs to be fixed. But at that meeting they didn't even want to look at our plan," Marius says. "Actually they said they set up the meeting to inform us that they would file a case for permanently removing the kids."

The campaign in support of the couple has been particularly well-supported in Marius's home country, Romania, and by Evangelical Christians worldwide, because the couple are Pentecostals.

Many protesters believe they are victims of discrimination on religious and national grounds.

Image copyright Alamy

There have also been other high-profile campaigns on behalf of immigrant families whose children have been forcibly taken into care in Norway, making the same claim.

One case involving a Czech family in Norway has led to a major diplomatic row between Norway and the Czech Republic. Czech President Milos Zeman accused Norwegian social workers of acting like Nazis - an allegation the Ministry for Children has described as absurd and unworthy of comment.

At first I thought that this case that we had experienced must be one in a million - there just can't be more madness than this Yngve, Grandfather of girl taken into care

But campaigners have also highlighted controversial cases where they say wholly Norwegian families have had children taken into care without adequate justification or attempt to find alternative solutions.

In an open letter of protest to the Children's Minister, 170 leading Norwegian professionals involved in child protection - lawyers, psychologists, social work experts - say Barnevernet is a "dysfunctional organisation which makes far-reaching errors of judgment with serious consequences".

Psychologist Einar Salvesen, one of the initiators of the letter, says: "There is a lack of what I'd call the human factor. A lack of empathy, really providing an atmosphere so people can learn… It's more like police interventions, more like we have to find out what's wrong with you."

Norway has long been proud of the resources it devotes to protecting children.

In 1981 it was the first country in the world to appoint a children's ombudsman - an independent official responsible for protecting children's rights. The idea has since been copied across Europe and beyond.

The child protection service, Barnevernet, stresses that in the vast majority of cases when it thinks something's going wrong in a family, it doesn't take the children away. It works with parents to solve the problems and keep the family together.

But the number of children and young people taken into emergency care rose by half from 2008 to 2013. That was partly in reaction to nationwide shock in 2005 over the killing of an eight-year-old boy, Kristoffer, who was beaten to death by his stepfather.

Most cases now don't involve parental violence, though, or alcohol- or drug-abuse. The commonest reason for a care order now is simply "lack of parenting skills".

That, in short, is the reason Barnevernet gave for taking away the four-month-old baby daughter of a young Norwegian father called Erik and his Chinese wife in the country's second city, Bergen.

Image caption Erik (right), his father Yngve (centre) and his sister (left)

Home videos of the little girl when she was three and four months old show her lying in her cot, apparently alert and responsive as she interacts with her parents.

But Barnevernet, the child protection service, said lack of eye contact, and other signs, revealed she was suffering serious psychological harm. They said her parents couldn't meet her emotional needs, partly because her mother was depressed, and Erik - to quote one social worker - was "simple".

However, Erik's never been diagnosed with any condition other than a slight lack of short-term memory when he was small. And the baby was never examined clinically by any health professional to establish if anything was wrong with her, and if so whether the parents could be at fault.

Just days before Barnevernet started their urgent assessment of the family, a doctor at their local health clinic found the little girl was developing normally.

But that wasn't mentioned at the court hearing that later upheld the care order. Nor, according to the girl's grandfather, Yngve, was other evidence the family put forward to try to win her back.

Image caption Yngve's grand-daughter

"We put forward a huge report on my son's psychological strengths and weaknesses," he says. "They haven't mentioned that by one word. So they are closing their eyes, and they say that we can only rely on the assessments that the people working for Barnevernet have made."

In the several years since then, Yngve - the Director of the State Archive in Bergen - has pressed the authorities, without success, to let him and his wife Bente, a professional photographer, take their granddaughter into their care.

Once a pillar of the establishment - he was personally appointed to his job by the King of Norway - Yngve is now a bitter critic of his country's child welfare policy.

"I grew up believing that Norway was the best system in the world, best for children, the UN are saying this all the time, and then I discovered that this cannot be the case," he says.

"At first I thought that this case that we had experienced must be one in a million. There just can't be more madness than this. And when I showed my face on TV in connection with this, a lot of people have contacted me, and they have showed me other stories that are even worse than the one that I have experienced.

"I am a senior civil servant, and I should really be a defender of Norway, and normally I am, but here it is something extremely wrong."

Yngve believes Barnevernet first became concerned about his granddaughter because initially she was cared for partly by her Chinese grandmother, to allow her mother to rest. That's common practice in China, but not in Norway, and Yngve thinks it made the authorities suspicious.

"I think this has to do with our Norwegian understanding of culture compared to other cultures," he says. "Barnevernet have their own definition of normality."

As the Norwegian media begins to investigate a story it has long ignored, one journalist has calculated that children with a foreign mother are four times more likely than other children in Norway to be forcibly taken from their families.

Parents have to know the law and live by it in Norway, regardless of background Kai-Morten Terning, Undersecretary at the Ministry for Children and Equality

There's no proof that cultural difference played a role in the removal of Yngve's granddaughter, or Marius and Ruth's children, though, and the authorities deny any discrimination in these or any other cases.

Kai-Morten Terning, undersecretary at the Ministry for Children and Equality, says he can't understand the reason for the international protests against his country.

"We don't have many children in alternative care, in comparison with, say, other Nordic countries," he says.

He says that following the open letter from the 170 professionals, the Ministry wants a "broad review of child welfare, to see what goes wrong and also learn from the best practice".

He adds: "We need to be better at helping families early, with assisted measures, because the child welfare service is a helping system, and most of the work they do is helping parents to become better parents."

He can't comment on Ruth and Marius's situation - or any other specific case - but when asked if mild corporal punishment would be sufficient reason for children to be taken into care, he says: "We have programmes for parents to avoid using corporal punishment… but parents have to know the law and live by it in Norway, regardless of background."

After more than four months when Ruth had to go through the routine of expressing her breast milk and bottling it up to take on the long drive to the two-hour, twice-weekly meetings with her baby son, last week, totally unexpectedly, he was returned to them.

But they don't expect any movement from the authorities on the other four children at least until after a court hearing at the end of May.

Media playback is unsupported on your device Media caption Ruth and Marius describe their quest for a family reunion

"We would like to explain to them the situation," Ruth says, ahead of another all-too-brief supervised meeting.

"But we cannot do that because we cannot talk about the case.

"They don't know when we're really fighting to not show our feeling. Because with the bigger ones we're told not to show any sorrow, because we make our child sad. So we really try to keep our tears to ourselves, till they're out of the door at least."

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