Israel's health ministry is investigating claims that Ethiopian women are being injected with a controversial contraceptive without their knowledge or consent.

Thousands of Ethiopian women are said to be receiving shots of Depo-Provera every three months in Israeli clinics. The contraceptive stops menstruation and has been linked to fertility problems and osteoporosis.

Yaakov Litzman, Israel's deputy minister of health, who has previously denied the practice, will lead the inquiry, a spokesperson announced on Wednesday.

The phenomenon was uncovered when social workers noticed the birth rate among Ethiopian immigrants halving in a decade. An Israeli documentary investigating the scandal was aired in December and prompted a popular outcry.

It revealed that women were started on a course of contraceptive jabs while still in transit camps in Ethiopia, some without being told they were being given birth control and many having no idea of the side-effects. When they eventually arrived in Israel, doctors continued the treatment unquestioningly. But the critical question remains unanswered as to who instigated the policy, with neither Israel nor Ethiopia willing to claim responsibility.

Sava Reuben, an Ethiopian who has lived in Israel since 1984, interviewed more than 35 women from her community for the film and found that 25 were still receiving contraceptive shots from healthcare providers.

Reuben spoke to one woman who believed she had been given a flu vaccination and had no idea she had been injected with Depo-Provera.

Another was pregnant with her fifth child when she arrived in the transit camp, where she would live for seven years. The woman in her thirties told Reuben that officials had gathered together all the new mothers in the camp and told them they would be given Depo-Provera as it would be too difficult for them to give birth Israel.

"No, we didn't want to take it, we refused. We said we didn't want it," the unnamed woman recalls in the film. She agreed to the injections only because she was told her immigration to Israel would be blocked and she would receive no further healthcare in the camps if she refused.

"This happened to many, many other women," Reuben said.

More than 50,000 Ethiopian Jews have immigrated to Israel in the past decade. The fast-growing community has struggled against bias. In 1996, thousands rioted when it was discovered that the Israeli health ministry had destroyed all stocks of blood donated by Ethiopians on the grounds that it might be contaminated with HIV.

Israel's health ministry has strongly denied allegations that the injections are part of a policy to control the growth of the Ethiopian community.

"The Israel ministry of health neither advises nor encourages the use of Depo-Provera injections and if they are being administered this is in despite of our view," a spokesperson said.

And yet Reuben claims to have discovered a letter from the health ministry to a clinic in Ethiopia in 2000 thanking doctors there for the large numbers of women they had treated with Depo-Provera.

"Why are only Ethiopian women being given Depo-Provera in Israel? It's supposed to be a last-resort contraceptive. Israeli health authorities claim the injections are a cultural preference but in our culture, to have lots of children is to be rich," Reuben said.

"It is my opinion that this is a deliberate policy on the part of Israel. They are taking advantage of women who are weak because they are new to the country, do not understand the language and who traditionally respect authority. It makes me more than angry."

Dr Mushira Aboodia, a gynaecologist working at Jerusalem's Hadassah medical centre, said the majority of Ethiopian women she had met received Depo-Provera injections.

"This is a policy that no one will admit. No one in Israel will take responsibility for the treatment in the camps but someone must have instigated it and it would not be in Ethiopia's interests to treat women preparing to leave the country," Aboodia said.

"Something is definitely wrong here. I'm very glad the ministry of health will be investigating the issue. They will need to do a thorough job."