Just days after the autopsy report of an inmate at a detention house in Danfeng county, Shaanxi province, showed that he died of "severe injuries", a top forensic expert on Wednesday challenged the findings, saying the death was "natural".

Xu Gengrong, 19, "suffered from liver and lung diseases, which caused his death", Bai Ningbo, the chief forensic doctor of procuratorate of Shaanxi, was quoted as saying in the Time Weekly yesterday.

The latest report comes even as authorities probe the role of two police officials in Xu's death on March 8, just a week after he was detained on suspicion of stoning a schoolmate to death.

Previous autopsy results showed Xu was "starved and suffered several injuries", but interrogation records from the local public security bureau stated he ate meals regularly except for the day before his death, when he refused to eat, Bai said.

Xu's relatives said they would ask for another autopsy and a possible exhumation of his body if they find that the results of the investigations into his death are "unfair", the paper said.

Xu was buried on Mar 16 after his family signed an agreement with the county government, which promised to investigate his death. His family was compensated with 120,000 yuan ($88,370), the Xinhua News Agency reported.

The provincial procuratorate had kept Xu's organs to carry forward the probe.

"I think we should not have buried my son so soon," the Time Weekly quoted Xu's mother, Cao Huiling, as saying.

Wang Xinghui, a family friend, said Bai has also recommended the family have a pathology expert join the investigation to find out the cause of Xu's "heart disease".

Following Xu's death, Yan Yaofeng, head of the Danfeng county public security bureau, was suspended from his post.

Wang Qingbao, a senior officer in charge of disciplinary inspection at the bureau, and Sun Peng, head of the criminal police team, are also under investigation for "dereliction of duty", local authorities said.

"Bullying and torture in police custody have become persistent problems over the past few decades," Jiang Jianchu, deputy procurator-general of the Supreme People's Procuratorate said earlier.

At least four other cases similar to Xu's have occurred in the last three months. Experts said that only when detainees are put under the control of "neutral" organizations would such incidents cease.

"Detention houses are supposed to be neutral ground Inmates should feel safe because they're supposed to be protected," said Chen Ruihua, a professor at Peking University.

"Detaining suspects is important, but they should be handled appropriately," said Wang Shunan, director of the School of Criminal and Judicatory Law of China University of Political Science and Law.

(China Daily, Xinhua, March 27, 2009)