A "gay conversion" group targeting the Jewish community was put on trial on Wednesday in New Jersey, accused of giving false promises to young men who paid for "therapy" to turn them into heterosexuals.

Jonah, formerly known as "Jews Offering New Alternatives to Homosexuality", faces accusations of fraud under the state's consumer protection act.

Therapeutic methods included the men being called "faggots" in role-playing sessions; stripping naked; and beating an effigy of their mother with a racket, according to court documents.

Jonah is being sued by three young men - two of whom are from Jewish Orthodox families - with the support of the Southern Poverty Law Centre, a non-profit civil rights group. The plaintiffs' attorney, David Dinielli, told jurors that the treatment was "junk science".

This is the first time consumer rights laws have been used to fight conversion therapy in the US. Jonah's treatment can cost more than $10,000 per year, according to court documents.

However, defence attorney Charles LiMandri said that the therapy had a religious rather than commercial character, and that there was therefore no argument for consumer fraud.