Then his back is to the cameras and he is talking to a few black kids who have put distance between themselves and the mob and he is explaining in those lisping tones that Don King is no brother of theirs and that they should love and respect people.

Two girls pose for photos with him and he wraps his arms - those limbs with their famed span - around their waists and they are delighted. He disappears into the limo and a three-car cavalcade moves out and the crowd swarms the black windows, still wanting.

Tyson is leaving behind high emotions; one woman is clutching his signed name and shouting "I've got it" while a white guy is upset at the security in Grosvenor House, screaming at the guard, saying, "you're nothing, I'll take you out here, you're f***in' nothin'."

Be like Mike.

It's impossible to know why the boxer's presence moves people so greatly. Perhaps it is just the age of celebrity - and Tyson looms large in that pantheon, the undisputed baddest ass on the planet as the public image goes. Maybe people just want to be up close to the man who chewed on Evander Holyfield's lobe and smashed cars and got sent down, beat up on elderly folk and once cried on a journalist's shoulder when he spoke about Cus D'Amato, the trainer who discovered him and was nothing less than a guardian angel.

But there is more to it. Tyson has often been likened to Sonny Liston, reviled in 1960s white America as the unacceptable face of Black America. But while Liston was brooding and uncomfortable in public, Tyson has appeal. Gold caret charisma. When he reaches out to people who want to be near him, their eyes light up. Mike Tyson fascinates, both on the canvas and on the street.

That is why George Michael found himself ignored when he walked into Heathrow off the same flight as the fighter and why Scary Spice found herself locked out of the Gucci store on Bond Street while he chose his threads. Celebrity is relative.

When he was still a kid and training under D'Amato, the gym in the Memorial Boxing Club in the Catskills was almost classically shabby - ring, peeling paint, yellowed clippings.

It's a wonder Burgess Meredith didn't turn up with a bucket and towels. Tyson loved the place and yet it is the very antithesis of his temporary gym in the ground floor of the Grosvenor House hotel.

American writer Joyce Carol Oates spent time with the fighter in those simple days and she has written essays on his rise and fall from grace. Back then, she was struck by the extraordinary personality, a combination of disarming warmth and soft politeness, yet one capable of executing frightening acts of violence in the ring.

Under D'Amato, that aspect of his personality was confined to the ring. After he died in 1985, Tyson fulfilled his prediction, leaving Trevor Berbick punch drunk as he decame the youngest heavyweight of all time in November 1986 (he was 20). Not long after things started sliding and then got warped.

"Everything was my fault," he said on Wednesday. "Although other people contributed, I've got to carry the weight by myself."

Would the 13-year-old Mike Tyson, the kid who jokingly warned D'Amato he'd sell his soul to become the heavyweight champ, would he recognise the 33-year-old man who will try to step back on the merry-go-round in Manchester next week? And what would he have thought if he could see himself?

Tyson's upbringing is the stuff of legend, but the thing is, he remembers it. He knows what waking up in abandoned buildings in Bedford Stuyvesant feels like, remembers what it was to mug folk for a living, of feeling alone. How weird it must be to recall that and be where he is now?

Talking of D'Amato once, Tyson said: "It occurs to me how much fun it used to be when it wasn't about money so much. He died and everything became money, money, money."

And that much hasn't changed. The fighter will earn $7.5 million on Saturday night and for that the world expects him to inject boxing with that illicit promise of danger, that carnal thrill which Lewis or Holyfield can't deliver. We expect him to demolish.

Next week, he will probably promise destruction, do the old heart of darkness thing. This week, though, he is content to soft-foot his way into the new century. Life for him has been worse; his wife Monica (Turner) arrives this weekend and in the ring he is a contender again.

And as he leaves his hotel, it is clear that for now anyway he has captured affections in London, of all cities.

"We love you Mike," yells someone in the rush, as his entourage merges with the traffic and sweeps around Speakers' Corner, where people gather on Sundays to listen to the oddballs and to laugh at them and call them crazy.