Frank Maloney, the man behind Britain's former world heavyweight champion Lennox Lewis's march to the top, is undergoing a sex change and living as a woman called Kellie, she told the Sunday Mirror.
The 61-year-old Englishwoman -- who stood for election to be London Mayor for the UKIP Party in 2004 -- has been married twice and has two daughters, but she told the newspaper she had always felt she was a woman.
"I was born in the wrong body and I have always known I was a woman," said Kellie, who as Frank Maloney engineered Lewis's 1993 world heavyweight title victory.
"I can't keep living in the shadows, that is why I am doing what I am today. Living with the burden any longer would have killed me.
"What was wrong at birth is now being medically corrected. I have a female brain. I knew I was different from the minute I could compare myself to other children.
"I wasn't in the right body. I was jealous of girls."
Maloney, who once had aspirations to be a Roman Catholic priest but grew disillusioned when he started studying to become one, said she had not felt it possible to reveal her secret desire to those involved in boxing.
"I thought maybe I can earn enough money that one day I can disappear and live a new life completely away as a female and no one would ever bother me," said Maloney, who ended his involvement in boxing last October.
"Once you come out of sport you are soon forgotten and that was what I was hoping would happen to me."
Lewis, now 48, issued a statement on Facebook in which he expressed his support for his former manager.
"I was just as shocked as anyone at the news about my former promoter and my initial thought was that it was a wind-up," said Lewis.
"The great thing about life, and boxing, is that, day to day, you never know what to expect. This world we live in isn't always cut and dried or black and white, and coming from the boxing fraternity, I can only imagine what a difficult decision this must be for Kellie.
"However having taken some time to read Kellie's statements, I understand better what she, and others in similar situations are going through. I think that all people should be allowed to live their lives in a way that brings them harmony and inner peace.
"I respect Kellie's decision and say that if this is what brings about true happiness in her life, than so be it."
Maloney said she intended to live as a single person and was now "mentally preparing" herself for the rest of her life.
Maloney, who suffered a heart attack in 2009 after discovering one of his boxers Darren Sutherland had hanged himself, caused a stir during the mayoral campaign when he remarked he would not campaign in one borough because there were too many gays living there.
"I'm not homophobic but in public let's live a proper moral life - I think that's important," said Maloney.
"I'm more for traditional family values and family life. I'm anti same-sex marriages and I'm anti same-sex families."