In an interview with The Independent, Dr James Watson said "there could be 1,000 different reasons" why women might want to abort a child, "many of them absurd", but society should do nothing to stop them.
Dr Watson was speaking from his home in New York following angry reaction to an article in the Sunday Telegraph published under the headline: "Abort babies with gay genes, says Nobel winner."
He said last night that he intended to sue the newspaper for giving the impression that he advocated aborting babies if future advances in science led to testing for a gay gene, whereas he simply believes that mothers should have the right to abort foetuses for any reason.
His comments provoked outrage in the gay community and among pro-lifers. However, his justification of them appeared to lead him into more extreme territory.
"During an interview, I was asked about homosexuality and I related a story about a woman who felt her life had been ruined because her son was a homosexual and she would never have grandchildren," he said. "I simply said that women in that situation should have a choice over whether or not to abort. I didn't say that foetuses found to have a gay gene should be aborted."
However, when asked where society should draw the abortion line, he replied: "Society shouldn't ... I don't see where you can draw the line. Some people might not want a child who is dyslexic. A woman could say that some day, if a gene were discovered for musical ability, and her child didn't have it, she might want to abort.
"Someone else might say, I do not want my child to be short because I love basketball and he'll be too short to play ... "
Gay rights groups and pro-lifers reacted angrily to Dr Watson's remarks. Kathleen O'Hanlan, a leading gay researcher and activist at Stanford University in California said: "Science doesn't designate homosexuality as a disease. Aborting a foetus for what is not a disease appears to be more like the practice of eugenics, more like the 1940s in Nazi Germany than the 1990s in the US or Britain. It will not be tolerated."
Professor Jack Scarisbrick, Director of the pro-life charity Life, said that the idea was a "horrible suggestion. All abortion is an offence to the right to life of a child and a violation of a mother," he said. "To do this because an alleged gene is going to result in homosexuality is a terrible discrimination."