One of China's best known dissidents, Chen Guangcheng, has escaped from house arrest and has released a video addressed to Premier Wen Jiabao.
In it he makes three demands, including one that Mr Wen investigate what Mr Chen, who is blind, calls the brutal beating up of his family members.
Rights activists say Mr Chen slipped out of his home in Dongshigu town in Shandong province on Sunday.
His whereabouts are unclear, but supporters say he is safe in Beijing.
An activist told the BBC he was at the US embassy in Beijing. But in an earlier Associated Press news report the embassy would not comment.
Mr Chen, 40, had been under house arrest since he was released from a four-year jail sentence in 2010.
In the video, delivered from a darkened room and posted online by Boxun, a Chinese dissident news website based in the United States, Mr Chen asks that:
- Premier Wen investigate and prosecute local officials Mr Chen says beat up his family members
- The safety of his family be ensured
- Corruption in general in China be dealt with and punished according to the law
Mr Chen names some local officials who told him that they "do not care about the law" and that "a few hundred people" were hired by the local government to "lock down" the village he lives in.
The Chinese authorities have come under international criticism for their treatment of him. At one point his daughter was barred from school. Many sympathisers who have tried to visit his home say they have been beaten up.
In the video, Mr Chen says: ''I may be free but my worries are for my family… my wife, my child, my mother. Perhaps because of my leaving, they may become the target of more brutal abuse.''
The plight of Mr Chen has become famous around the world. US Secretary of State Hillary Clinton has repeatedly called for his release and is due to visit Beijing next week.
An activist based in the United States who has been in close contact with Mr Chen confirmed that the dissident had left Shandong - about eight hours' drive from Beijing.
"Now I can share with you Chen is now in the 100% safe location in Beijing. That's how much I can share with you,'' Bob Fu, founder of ChinaAid, based in Texas in the US, told the BBC via email.
Another activist told the BBC he was at the US embassy, but this has not been confirmed.
The authorities appear to be moving against those believed to have been involved in Mr Chen's escape.
Reports on Friday said that local authorities had surrounded the house of Mr Chen's brother, Chen Guangfu, and nephew, Chen Kegui, in Dongshigu, near Linyi.
Ms He told AP that the younger Mr Chen "took a cleaver for self-defence''.
''He said he hacked several people with the cleaver and wounded them," she said.
Mr Fu said in the same report that Chen Guangfu and Chen Kegui had been detained by police.
Mr Fu later told Agence France-Presse that Ms He had been arrested at her home in Nanjing on Friday.
Chen Guangcheng, who has been under house arrest for almost 20 months following his release after serving four years in jail, is known as ''the barefoot lawyer''.
He lost his sight in childhood. He has no formal legal training as the blind were not permitted to attend college.
He is known for revealing rights abuses under China's one-child policy and has accused officials in Shandong province of forcing 7,000 women into abortions or sterilisations.
He has also advised farmers in land disputes and campaigned for improved treatment of the disabled.
The Chen affair comes at an unwelcome time for China's leaders, who have been embroiled in a lurid political scandal involving disgraced former party boss Bo Xilai.
Mr Bo - a high flier once expected to reach the top echelons of office - has not been seen in public since he was removed from his political posts, in the biggest political shake-up in China in years.
Mr Bo's wife is being investigated over the death of British national Neil Heywood.