Human rights activists say a prominent dissident lawyer in China has escaped from house arrest and released a video appealing directly to the central government.

Chen Guangcheng was imprisoned after waging a campaign against forced abortions and was confined to his home once he was released from his four-year jail sentence in 2010.

In a video posted on the internet, Mr Chen made three demands of the Chinese Premier Wen Jiabao, including one to keep his family safe.