Revelations that Sweden forcibly sterilised thousands to "weed out inferiors" may sound like a sinister science fiction plot to some Westerners, but the practice has a long history in the United States.

By the 1930s, some 30 American states had passed laws allowing the involuntary sterilisation of the mentally ill. Between 1907 and 1960, about 60,000 people were given vasectomies or tubal ligations, according to Prof Gerald Gelb, an academic and author of The Mad Among Us.

"By the late 19th century, there was a fear that there were degenerate groups in the population and that if they continued to breed and intermarry it would pull down the general level," he said. "Out of this came the belief that perhaps the best way to deal with this would be to sterilise defectives," including criminals.

Ethnic groups in the US were also targeted. In 1975, the government conceded that the Indian Health Service had conducted a secret programme of forced sterilisations on about 40 per cent of Native American (Indian) women.

Some anti-abortion groups also argue family planning clinics have similar motives by setting up operations in the inner cities to target poor minorities.

A eugenics programme was introduced in the 1920s in Canada, where victims have filed dozens of suits for compensation. Britain also allowed involuntary sterilisations as did Sweden, Norway, Finland, Estonia and a Swiss canton.

While the West has expressed revulsion at forced sterilisations conducted in China, India and Nazi Germany, Prof Gelb says the drive for an Aryan race began in the US. He notes that 75 per cent of forced sterilisations occurred in California, Virginia and Kansas where there was less resistance to the practice.

Catholics and human rights groups did eventually lobby to have states overturn the laws allowing forced sterilisation and most did so during the 1970s.

Prof Gelb said there were no known laws still on the statue books, but family planning opponents argue that the aims of organisations such as Planned Parenthood amount to a new sort of eugenics.

Congressman Chris Smith alleges that abortion clinics are purposely placed in inner cities to target certain groups and the anti-contraception group, the Population Research Institute, opposes Washington state's vasectomy programme on similar grounds.