Religious organisations are harming homosexual teenagers by offering bogus “cure” therapies, according to a US gay group.

The National Gay and Lesbian Task Force Policy Institute claims that Christian groups in Florida are offering parents therapy to stop their child becoming gay.

The report, Youth in the Crosshairs: The Third Wave of Ex-Gay Activism, reveals how Christian groups such as Exodus International and Focus on the Family promote widely discredited theories on the root of homosexuality and now recommend “prevention” and conversion therapy treatments despite the growing body of research that shows these treatments to be ineffective and even harmful for many participants.

One conclusion of the report claims to show that, in what the group calls the “third wave of ex-gay activism”, ex-gay programmes and their evangelical Christian right allies are focusing less on “curing” adults of homosexuality and more on preventing its development by targeting parents, children and adolescents.

The study claims groups are recommending that parents commit their children to treatment of “prehomosexuality” even if it is against their children’s wishes. Heterosexual youth are also being recruited in schools and churches to spread the message that homosexuality is a treatable mental illness.

“One of the most disturbing accounts in this report is a case involving a 5-year-old boy who was subjected to conversion therapy to address ‘prehomosexuality.’ The case involves a psychologist who claims that his theories and treatments are scientific,” said study co-author Jason Cianciotto, the Policy Institute’s research director. “To the contrary, conversion therapy is opposed by nearly every medical and mental health professional association, including the American Academy of Pediatrics.”

He added, “Studies cited by ex-gay leaders to support their claims suffer from fatal methodological flaws, and are contradicted by respected, peer-reviewed academic research. Tragically, ex-gay and evangelical Christian right leaders are using bogus theories and discredited research to frighten parents into doing something more likely to harm than help their children.”

Alan Chambers, President of Exodus International, told the Associated Press he had not seen the report but said the ministries are successful, “The truth is that there are hundreds of thousands of men and woman like me who have found that change is possible,” said Chambers, who considers himself to be a former gay person.