A California state senator has come out as a homosexual after many years as a staunch opponent of gay rights.

Republican Roy Ashburn has admitted to being homosexual, telling a radio audience he felt compelled to answer rumours that he had been in a gay nightclub prior to his arrest last week for driving under the influence.

The 55-year-old father of four said he owed the public an explanation as he had consistently voted against gay rights measures in the state Assembly since 1996, when he was first elected to the State Assembly.

He said he only voted that way to reflect the concerns of his constituents.