The United Nations envoy on torture has arrived in Beijing for the first such visit to China.
It has taken 10 years for the Chinese government to agree to allow such a visit.
Manfred Nowak is to visit Tibet and the Muslim-majority region of Xinjiang in China's far northwest, home of a large population of ethnic Uighurs. He also is to visit Chinese prisons.
China has the world's biggest prison population and is dealing with a number of cases in which people have been wrongly convicted and, in some cases, executed after giving forced confessions.
China agreed to the visit in August. Mr. Nowak will be in China through December 2nd.