British boxer Tyson Fury may be a heavyweight champion, but the greatest fight of his life is taking place outside of the ring.

FOX's Jared Max reports:

11 months since he won the world heavyweight title in an upset over Vitali Klitschko, Tyson Fury is coming clean about why a rematch with Klitschko has been cancelled twice. The reason he's medically unfit because of mental illness and the drug and alcohol abuse he has succumb to.

In an interview with Rolling Stone magazine, the 28-year-old fighter said, "they tell me I've got a version of bi-polar, I'm a manic depressive, I just hope someone kills me," he says, "before I kill myself."

Fury could lose his WBO and WBA heavyweight titles because of inactivity and a potential withdrawal of his boxing license. British Boxing Board of Control will meet next Wednesday to discuss Fury, who admitted to Rolling Stone, "I've been out drinking out Monday to Friday to Sunday, I've taken drugs, cocaine on many, many occasions the last six months."

Jared Max, FOX News.

Follow Jared Max on Twitter: @Jared_Max