Newly released documents have shown that the US military was considering the development of a chemical weapon to turn enemy soldiers gay.

Edward Hammond, of Berkeley's Sunshine Project, used the Freedom of Information Act to obtain a copy of the proposal from the Air Force's Wright Laboratory in Dayton, Ohio and passed it to CBS 5.

According to the document the Air Force requested $7.5m for the development of such a weapon, but the proposal was rejected.

"The Ohio Air Force lab proposed that a bomb be developed that contained a chemical that would cause enemy soldiers to become gay, and to have their units break down because all their soldiers became irresistibly attractive to one another," Hammond told the TV station.

"The notion was that a chemical that would probably be pleasant in the human body in low quantities could be identified, and by virtue of either breathing or having their skin exposed to this chemical, the notion was that soldiers would become gay,"

The ideal was first mooted in 1994, after the Cold War had ended. In the proposal the weapons was described as "distasteful but completely non-lethal".

The news has caused outrage among sexual rights groups. "Throughout history we have had many brave men and women who are gay and lesbian serving the military with distinction," said Geoff Kors of Equality California.

"So, it's just offensive that they think by turning people gay that the other military would be incapable of doing their job.

"And it's absurd because there's so much medical data that shows that sexual orientation is immutable and cannot be changed."