The older brother of Chinese activist Chen Guangcheng has fled the closely-guarded village where he lives for the capital, Beijing.
Chen Guangfu is seeking legal help for his son, who faces charges after a clash with local officials.
Lawyer Ding Xikui told the BBC that Chen Guangfu wanted to consult lawyers in Beijing over his son's case.
Chen Guangcheng, who is now in the US, has expressed concern that his relatives could face reprisals.
The blind activist triggered a diplomatic crisis between the US and China when he fled house arrest to the US embassy in Beijing in late April.
He has now been allowed to travel to the US with his wife and children to study, but his relatives remain in China.
They live in Dongshigu village in Shandong province, which has been under tight security.
Ding Xikui told the BBC that he met Chen Guangfu on Thursday morning. "It seems like he escaped in the night and took a bus," he said.
He said Mr Chen wanted to "consult a few lawyers" over the constraints to his freedom and to help his son.
Chen Kegui has been charged with "intentional homicide" after a clash with local officials who came to his house shortly after Chen Guangcheng disappeared. His relatives say he was defending himself.
Mr Chen's wife, Ren Zongju, previously told of how officials came to her home and attacked her son.
"They started fighting inside the house. So many people were beating him. His face was bleeding, and his legs. His trousers were ripped," she said.
Mr Chen also detailed how he himself was detained for days, interrogated and beaten after his brother's escape.
Cheng Guangcheng's case highlights how Chinese authorities often seek to punish family members of dissidents, according to the BBC's Martin Patience.
While his escape has been hailed as a victory by his supporters, Chen Guangcheng has said that it would be his family who continue to bear the consequences.