Beijing ? A bishop who led an underground congregation of Roman Catholics and was repeatedly detained in China for his loyalty to the Vatican died in police custody, a monitoring group said Tuesday.

Bishop Han Dingxiang, 71, was cremated within six hours of his death Sunday and buried in a public cemetery with no priests or other faithful present, both groups said.

Han, who had been under house arrest or other forms of detention for nearly eight years, died while being treated for an unspecified illness, the U.S.-based Cardinal Kung Foundation said. The group, which has long had close contacts with China’s underground church members, did not cite sources for its information.