An Orthodox scientific group has sparked controversy by giving a platform to a Jewish organisation that believes homosexuality can be cured.
The Association of Orthodox Jewish Scientists invited Arthur Goldberg to speak at its annual convention in Connecticut last month.
Mr Goldberg is a proponent of reparative therapy, which seeks to transform gays and bisexuals into heterosexuals through therapy.
In 1999, he co-founded JONAH (Jews Offering New Alternatives to Homosexuality). Opponents claim such therapies are ineffective and even harmful.
An opposition group, Truth Wins Out, catalogues some of JONAH's unorthodox methods on its website.
In a recent Web video, a former "patient" claimed he was told to strip in front of a mirror during a therapy session and to touch his genitals in order to reaffirm his masculinity.
Truth Wins Out's executive director Wayne Rosen said the AOJS's invitation to Mr Goldberg gives credence to such methods.
"The invitation was reckless, irresponsible and added pain to the victims of this therapy," said Mr Rosen.
An AOJS spokesman was unavailable for comment. But Mr Goldberg said the AOJS was a significant forum to address.
"These are Jewish scientists and Orthodox scientists and the objective was to basically explain what the science is all about," he said.
He explained that he used his AOJS talk to list "the top ten myths of homosexuality" such as that "people are born gay".
He conducted a telephone interview in front of the audience with an anonymous man who claimed he was cured.
And he said there was scientific evidence that reparative therapy worked, citing research by the National Association for Research and Therapy on Homosexuality.
But Michael Salamon, a Long Island psychiatrist who has counselled gay men forced into arranged marriages, said the American Psychiatric Association considered reparative therapy "at best no good and in its worst forms dangerous".
"That's been my finding on a clinical basis," he said.