A man has been arrested on suspicion of killing 11 men in China, the official Xinhua news agency confirmed on Sunday, breaking its silence over the capture of a loner dubbed the "cannibal monster".

News reports from China and Hong Kong on Friday alleged the 56-year-old, a convicted murderer who was released from prison in 1997, had chopped up the bodies of the dead and sold the flesh to unsuspecting consumers.

Zhang Yongming was detained more than two weeks ago in his village in southwest China, where he was known as the "cannibal monster", the Guangxi News website reported last week.

It quoted residents as saying they had seen green plastic bags hanging from his home, with what appeared to be white bones protruding from the top.

The influential Xinhua made no mention of cannibalism in its "exclusive" story on Sunday of the arrest of the man it called "the alleged serial killer" and made few of the graphic revelations contained in the earlier reports.

A previous Xinhua report said only that Beijing had dispatched a team of experts to Yunnan province, where the accused lives, to supervise an investigation into missing teenagers.

Almost all last week's reports on the grisly case -- which made headlines around the world -- were later removed from Chinese websites and online searches for the words "missing in Yunnan" were also blocked.

Chinese media normally face few restrictions on reporting about non-political crimes, and it was not immediately clear why details of the Yunnan case had been originally censored.

Cannibalism is a particularly sensitive subject in China, where it was practised as a survival tactic during periods of mass starvation, for example in the wake of a failed industrialisation drive launched in the late 1950s.

"A large amount of physical evidence and DNA comparisons show that Zhang Yongming from Nanmen village, Jinning county, killed the 11 males," Sunday's report said, citing the ministry of public security.

"After the murders, Zhang used various means, including dismemberment, burning and burial, to destroy the evidence."

Zhang is said to have attacked his victims while they were walking alone near his home.

Hong Kong newspaper The Standard had said police discovered human eyeballs preserved inside wine bottles -- "like snake wine" -- and pieces of what appeared to be human flesh hanging up to dry when they entered Zhang's home.

Police feared that Zhang had fed human flesh to his three dogs, while selling other parts on the market, calling it "ostrich meat", according to The Standard.

Xinhua's Sunday report quoted the public security ministry as saying that it would work with local authorities to punish any police officers found to be guilty of dereliction of duty.

Internet users have expressed dismay that officials had not tackled the case sooner.