Four drug addicts have been arrested in the southern Chinese city of Shenzhen for allegedly beating another addict to death in a police-run rehabilitation center.

The killing occurred on Oct. 31 at the drug rehabilitation center affiliated to the Bao'an District Branch of the Shenzhen Municipal Public Security Bureau, said a spokesman with the Shenzhen Municipal Procuratorate.

The police branch reported the case to the procuratorate on Nov. 8 and the procuratorate immediately sent forensic doctors to identify the cause of the victim's death, the spokesman said.

Forensic doctors found the victim's ribs were broken. They believed the victim, who had pneumonia, died of heart and lung failure caused by "outside force of blunt objects", the spokesman said.

The procuratorate has sent staff to the Bao'an police branch to investigate the case, he said.

"So far, we haven't found any staff members of the center were involved in the incident, but we're investigating whether there was any dereliction of duty," he said.

The spokesman did not provide further details.

Local media reported Wednesday that the victim was Luo Haigang, 25, a migrant worker from central China's Hunan province, who had worked in Shenzhen for more than five years. He was sent by police to the Bao'an rehabilitation center on Oct. 12 for a six-month compulsory treatment.

There was no indication on how long Luo had been an addict.

A police spokesman was quoted by the Southern Metropolitan News as saying that police officers at the center were informed by Luo's roommates on the night of Oct. 31 that Luo had suddenly fallen ill, and they immediately sent Luo to the center's clinic and then transferred him to a hospital.

"Emergency treatment lasted about one hour, but failed to save his life," the spokesman said.

The police notified Luo's relatives on Dec. 7 that four drug addicts at the center had beaten Luo, which led to his death, and the four suspects had been detained, according to the newspaper.

(Xinhua News Agency December 13, 2007)