Beijing - China has detained an environmentalist and writer on suspicion of subversion after he initiated an independent investigation into the May 2008 Sichuan earthquake, a rights group said on Wednesday.

Tan Zuoren, a local activist based in Chengdu, Sichuan Province, was accused of "inciting subversion of state power" after mobilizing volunteers to investigate why school buildings collapsed in the earthquake, the Chinese Human Rights Defenders (CHRD) said in a statement.

After the earthquake, Tan had posted online a number of commentaries critical of the government, it said.

In February 2009, he had called for volunteers to travel to Sichuan to investigate the quality of the collapsed buildings, and to also examine the treatment of parents whose children died during the earthquake, the group said.

The CHRD said Tan's home was also searched on the day he was detained, and that DVDs, manuscripts and documents were confiscated.

He is one of several people believed to have been detained in the earthquake aftermath for alleging that corruption was behind the collapse of the school buildings. Others include Huang Qi, the director of the Tianwang Human Rights Center, who is still being held after reporting on protests staged by families of the schoolchildren.

The government maintains that the magnitude and intensity of the quake was the main cause of the damage. (dpa)