Boxing legend Mike Tyson is keen to up his ­profile in China but is struggling to get to grips with the country's sardonic sense of humor, ­judging by his online "Weibo" debut.

The former world heavyweight champion opened a verified account on the Twitter-like Sina Weibo service on Monday, and asked in his ­second posting, "Who's the best fighter in ­China?"

A popular response was "chengguan," China's widely despised enforcers of urban management officers, who have a reputation for brutality.

But the boxer, who retired in 2005 after a ­career noted for controversy inside and outside the ring including a rape conviction, replied, "Who is Chengguan? A tough man? I've never heard it."

"Many guys talking about Chengguan as a great fighter? Still not a clue about him..." he added later.

Tyson was following celebrities including Brad Pitt and David Beckham on to Sina Weibo, and already had more than 110,000 followers by press time.

Tyson's posts quickly became among the most-reposted on Weibo, with tens of thousands of ­followers commenting on a potential fight ­between Tyson and chengguan.

"They will be the ones biting your ear," said one poster on Tuesday, referring to the 1997 World Boxing Association heavyweight championship bout which was stopped after Tyson bit Evander Holyfield.

"You fight others in the ring legally in US. Chengguan fight others in the street legally in China," said another sarcastic comment.

Excessive zeal from chengguan enforcers regularly attracts media attention in China.

Another poster told Tyson, "If you really want to challenge our chengguan, just sell your American hamburgers in our Chinese streets."

American Tyson, born on June 30, 1966, is a former ­undisputed heavyweight champion of the world.