The United Nations is criticizing China for failing to provide details about detainees, including some who reportedly have died in custody.
The U.N. Committee Against Torture Friday questioned a Chinese delegation about a wave of arrests following March riots in Tibet -- and the fate of those detained.
The Geneva panel is investigating reports by international human rights groups about reported violence against inmates in Chinese prisons, including alleged beatings, sexual abuse and torture.
Chinese envoy Li Badong said Chinese law bans torture, and that authorities investigate reports of violations.
But committee member Felice Gaer told reporters in Geneva that there is still too much information missing about what happens to people detained by Chinese authorities.