Lennox Lewis has urged Mike Tyson to "straighten himself out" so that the two can meet in the ring, with Lewis's undisputed world heavyweight title at stake, in a contest that would provide the British fighter with the most lucrative night's work of his career.

While the 34-year-old champion's next opponent is most likely to be the undefeated Michael Grant, possibly in London next spring, victory over Tyson remains an unfulfilled ambition.

"He is a boxer of my era and most of his fans and my fans want to see it," Lewis said. "Tyson is the biggest fight out there for me right now. I think he's been a naughty boy lately but as soon as he puts that right and has a couple of wins to go back on that positive path, they can put the fight together."

However, boxing politics could stand in the way of Lewis-Tyson taking place any time soon, mainly because Tyson is tied to a contract with Showtime Television whereas Lewis's fights are screened in the US by the rival network HBO. Neither would readily surrender rights to their most marketable heavyweight.

Tyson has been installed as the number one challenger for the World Boxing Organisation's (WBO) title, the one significant governing body whose championship was not decided by Lewis' victory over Evander Holyfield. The WBO champion is the Ukrainian Vitali Klitschko.

With the overseas TV rights to Tyson's fights also now German-controlled, it does not take a detailed understanding of boxing's finer nuances to realise that Tyson-Klitschko for the WBO title is more easily arranged than Lewis-Tyson.

Lewis's promoter, Panos Eliades, who once fancifully suggested Nelson Mandela had been directly involved in negotiations to take Lewis to South Africa, now says he has received approaches from Beijing and Shanghai to take the last true heavyweight champion of the 20th century to China.

"My telephone has hardly stopped ringing since Lennox beat Evander," said Eliades, adding that he had also received offers from Tokyo, where Tyson famously lost to Buster Douglas almost a decade ago, and Toronto, where Lewis lived with his mother after leaving London aged 12.

But Grant is believed to be the favoured option of HBO, and Lewis was at ringside in Atlantic City on Saturday to see the 6 ft 7 in American beat Poland's Andrew Golota.

"Grant's a big guy with a lot of strength, but I'd say he lacks the amateur experience of people like myself," said Lewis, who won gold at the Seoul Olympics in 1988.

"I'm taking it all in slowly and letting my people decide where I go from here. It's been a great ride but it's not over. There are still some hills to climb and I've got to see what else I can achieve."