The London Mayor also said he had no plans to call for the sacking of Assistant Commissioner John Yates, who yesterday expressed ”regrets” over failures during the Scotland Yard inquiry.
There was huge media interest in Mr Johnson’s private life amid claims in 2004 that the then editor of the Spectator had an affair with columnist Petronella Wyatt.
Speaking at his monthly grilling by the London Assembly, he detailed how he had discussed with police in 2006 that he may have been a victim.
He said he told detectives he would help as part of a prosecution ”if you need me” – but understood he would not be required.
Mr Johnson added: ”Quite frankly, why on earth should I go through some court case in which it would have inevitably involved going over all the pathetic so-called revelations that the News of the World had dug up… Why should I, when the police had made it clear to me when they had abundant evidence?”