LONDON (Reuters) - Troubled former world heavyweight boxing champion Frank Bruno has admitted his drug problems have returned after saying he had stopped using cocaine.

In Saturday's Sun, the 44-year-old who won the World Boxing Council (WBC) title against Oliver McCall in 1995, said: "I got high on the stuff and I'm deeply ashamed. This was a one-off though.

"I have promised my daughters I will never touch the filthy stuff again -- and it's a promise I intend to keep."

The newspaper article quotes an unidentified prostitute as saying Bruno snorted "14 lines of cocaine" in her company last Sunday.

Bruno, who retired on medical advice after losing to Mike Tyson in 1996, has suffered well-publicised mental problems in recent years and was treated at a psychiatric hospital in 2003.

Bruno admitted in his autobiography that he began using cocaine in 2000, blaming the drug for his mental problems.