Boxing: Miracle I am still alive, says Tyson

When Mike Tyson left town after a recent series of those fashionable "An Evening With..." engagements around the country, he also left several questions unanswered. These concerned his conviction for rape – the subject of demonstrations by women's groups that caused the cancellation of one dinner date in Glasgow – his drink and drug addiction and the infamous chewing of Evander Holyfield's ear.

All were taboo, the paying punters being informed that any questions they wished to ask him had to be put in writing in advance. The reason why the former world heavyweight champion, the self-styled "baddest man on the planet", was uncharacteristically coy became evident when it was later learned that all was being revealed in a new documentary movie about his turbulent life.

When Tyson turned up to promote it at the Cannes Film Festival, he claimed he had agreed to make it to help him "repent and reflect" on the years of torment and turmoil, saying: "It is a miracle I am still alive. I have lived a wild and strange life. I have had physical altercations with dangerous people and slept with guys' wives and they've wanted to kill me. I am just happy to be here."

Iron Mike, who will be 42 tomorrow week, is in rehab after years of alcohol and drug abuse. "I am not getting high today, but I am not promising I am not getting high tomorrow," he said. "I am in an abysmal world trying to figure it out." He is also co-operating on his memoirs with a leading US author, Larry Sloman, which he says he also hopes will rehabilitate him in the eyes of the public.

The film has been described as both dark and violent. Tyson says on reflection he is embarrassed about it "because there are a lot of things in it that peopledidn't need to know. It's all very painful stuff". He says it raises questions he himself cannot answer: "I don't know who I am. That may sound stupid, but I really have no idea. All my life I've been drinking and drugging and partying and all of a sudden this comes to a stop. I felt like one of those barbarian kings coming to conquer the Roman Empire. I was crazy."

Tyson claims he was born an addict but says this is not to blame for his schizophrenic persona. He is a man of violent mood swings who can also display a disarming degree of intelligence. Bloated and strangely reticent of late, he has taken to wearing a bowler hat on top of his tattooed head which makes him look like a latter-day Oddjob.

This is the man who struck terror into his opponents, kept Bengal tigers in his back yard, and sank his teeth into not only Holyfield's ear but Lennox Lewis's thigh, threatening to eat his babies.

Yet during his spells in prison Tyson spent many hours in solitary confinement reading the great philosophers, and he says that today he admires the work of Machiavelli and Tolstoy. "All these guys, for some bizarre reason, are in pain," he said.

Now his own pain is as much fiscal as physical, for Tyson, who lives near Las Vegas, is deeply in debt, owing the taxman millions. He has been declared bankrupt despite receiving more than $30 million (£15m) for several of his fights and earning $300m in his career.

It is 11 years since Tyson gnawed off part of Holyfield's right ear in Las Vegas and, astonishingly, we now learn that Holyfield himself is also in financial distress despite amassing one of the biggest fortunes in boxing. Holyfield's career has brought in $250m. Now, at 45, he slurs his speech and refuses to quit the ring. Recently his 109-room, $20m mansion – which sits on 235 acres at the end of Evander Holyfield Avenue in Atlanta and has 17 bedrooms, three kitchens, a bowling alley and its own movie theatre – was put up for auction.

Though this was later called off, he is said to be struggling with $15m in mortgages, is behind on child support – he has 11 children by seven different women – has been sued for not paying $550,000 in loans for landscaping and reportedly has a problem with a $1.1m promissory note.

Holyfield claims he is not broke but "just not liquid", adding: "I feel kind of sad because things have always been positive, and now everyone wants to jump on me like I'm the worst person in the world and I went and blew all my money."

In a 24-year career spanning 53 fights, the four-time world champion has lost seven of his last 13 bouts and his career has been in steep decline. The "Real Deal" went through a dismal stretch that produced only one win, prompting the State of New York to strip him of his licence five years ago.

Resisting calls to retire, Holyfield returned from a two-year lay-off last October to bid for Sultan Ibragimov's World Boxing Organisation heavyweight title in Moscow. He lost on a unanimous decision, but insists he will keep on fighting until he becomes the undisputedworld champion

Throughout ring history, dating back to Joe Louis, many big-earning world heavyweight champions have ended up strapped for cash like Tyson and Holyfield. Smokin' Joe Frazier, too, has reportedly burned through most of his money.

But not all of them finish penniless, of course. Larry Holmes owns half of Easton, Pennsylvania, where he lives; George Foreman lives off the fat of his lean grilling machines; Lennox Lewis has stashed away millions; Rocky Marciano died a millionaire; the Ukrainian Klitschko brothers Wladimir and Vitali are more than comfortable; and Muhammad Ali, although he has been ravaged by illness, is by no means broke.

Penury is the end result in many sports, but it seems that boxers, particularly heavyweight boxers, are more vulnerable than most to losing both their marbles and their money. The harder they fall, the harder-up some ofthem become.