Former world champion Lennox Lewis has declared the heavyweight division "dead" and criticized current champions Wladimir and Vitali Klitschko for fighting sub-standard boxers.

Lewis, 46, retired in 2003 as the WBC and IBO champion after defending his titles with a sixth round technical knockout of Vitali Klitschko due to a cut, but says the heavyweight division badly needs more exciting fighters to come through.

"Right now, the heavyweight division is dead," London-born Lewis told German magazine Stern. "The Klitschko brothers and their opponents are just filling their bags (with cash). Their opponents will not improve; they wouldn't have even made sparring partners for me."

The aging Ukrainian brothers hold all the major heavyweight belts between them. Wladimir, who turns 36 on Sunday, holds the WBA, IBF, WBO and IBO titles while Vitali, 40, is the WBC champion.

Wladimir knocked out former cruiserweight champion Jean-Marc Mormeck on March 3. The Frenchman was hopelessly outclassed and Lewis fees the Ukrainian brothers’ title fights are a poor advert for the sport.

"At some point, the referee steps in and stops the fight. They are boring," said Lewis.

"If you are looking to find the best boxer in the world it must be decided by an epic fight. Not this circus."

Wladimir Klitschko has already answered criticism of his fights and before the Mormeck bout refused to apologize for making his so-called "easy" fights look one-sided.

"Maybe it looks simple and one-sided, but it demands a lot of work and concentration and you have to be right on the ball," he said.

"It doesn't matter what kind of mood you are in, what kind of physical shape you are in, you have to show your best.

"If our fights were kind of sloppy and we were getting punched in the face, probably that would be exciting for the fans."

Lewis has no plans to return to the ring, but says he could be persuaded if he was offered an astronomical purse.

"For 100 million I'd come back. For that I would take off my pajamas and go to the gym."