BEIJING - Police in southwest China have detained a man suspected of murdering more than a dozen boys and young men, chopping up their bodies and selling the flesh to unsuspecting consumers, reports said Friday.

Police made the gruesome discovery during an investigation into the disappearances of male teenagers in Yunnan province in recent years, according to reports in Hong Kong and Chinese media.

Zhang Yongming, 56, was detained two weeks ago in his home village of Nanmen in Yunnan and is being investigated over the murder of a 19-year-old man in late April and the disappearance of several others, the Guangxi News website reported.

Police searching Zhang's home found the young man's cellphone, bank card and other evidence, according to the website, which said more than a dozen other teenagers had gone missing from the village over the years.

It said Zhang, a loner who never talked to his neighbours, had previously served almost 20 years in jail for murder and was known in the village as the "cannibal monster".

And 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.

Hong Kong newspaper The Standard 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.

Local police declined comment when contacted by AFP, saying information would be made available "at an appropriate time", and almost all reports on the case were removed from Chinese websites as of Friday.

Online searches for the words "missing in Yunnan" were also blocked.

The official Xinhua news agency said Beijing had dispatched a team of experts to Yunnan to supervise the investigation into the missing teenagers, but did not refer to the gruesome details contained in other reports.

Families of the missing originally suspected they had been kidnapped and forced to work in illegal brick kilns, Xinhua said, adding that two local police chiefs had been sacked and the government had urged a swift resolution to the case.

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

Cannibalism is a sensitive subject in China, as it is known to have been practiced as a survival tactic during periods of mass starvation, for example in the wake of a failed industrialisation drive launched in the late 1950s.

Individual cases of cannibalism were also recorded during the Cultural Revolution from 1966 to 1976, when it was carried out as a symbolic act against perceived enemies of the communist cause.

"Yunnan is a border province, and it's very conscious of its relative backwardness compared with other Chinese provinces," said Joseph Cheng, a China expert at City University of Hong Kong.

"It hurts the image of Yunnan province, and that's probably the motivation for the cover-up."