In a statement, the police said they "cannot allow the holding of this forum which will advance and legitimize the cause of homosexuals in Singapore."

Public gatherings in Singapore require a police permit. The forum, organized by gay rights activist Alex Au, was scheduled to be held this Sunday.

"The mainstream moral values of Singaporeans are conservative, and the Penal Code has provisions against certain homosexual practices," the police said in a letter to Au dated May 23.

"It will therefore be contrary to the public interest to grant a public entertainment license."

The government in 1997 rejected attempts by Au and his associates to have their gay and lesbian support group People Like Us registered as a society. The group however maintains a website.

Au declined comment on the denial of the police permit for the forum.

"That's something I need to organize my thoughts on," he told AFP.

"We need to do a bit of brainstorming as to what we'll do next."

A recent groundbreaking survey by volunteers from People Like Us showed that majority of Singaporeans can accept a gay member of the family, agree that oral sex between adults in private should not be prohibited, and feel that employers should not discriminate against homosexuals.

Open displays of homosexuality are frowned upon and oral sex is punishable by life imprisonment in Singapore.