Chinese police have said the blind activist Chen Guangcheng did not break the law when he fled his home in eastern Shandong province for the capital, according to a friend.

Chen had been held for 19 months under a harsh regime of house arrest, but there was no legal basis for the measure and the Chinese government denied that his movements were restricted.

Supporters have been detained and questioned following Chen's escape. It is thought that He Peirong, who said she had driven Chen to safety, remains detained. Guo Yushan was released on Monday and told the Wall Street Journal he was treated civilly during his questioning.

The activist Hu Jia, who was also questioned, said officers told him: "They [Chen, He and Guo] are all free citizens. For them to come to Beijing and so on, there is nothing illegal about it. They are free to do so. They did not do anything wrong, they have no legal trouble. We just want to understand the situation and verify it."

A lawyer is believed to be facing pressure from authorities after agreeing to represent Chen's nephew Chen Kegui, who is understood to be on the run after lashing out with a knife at men who broke into his house to try to detain his father.

On Monday Liu Weiguo told the Guardian: "It was in time of need that he found me and I have taken the case. His wife, who had no one to turn to, found me, so I have no choice."

Other lawyers who offered to help Chen Kegui said Liu had texted on Tuesday asking them to take over the case as soon as possible. when contacted by phone Liu said he was OK but that it was not convenient to talk.

Friends have said Chen Guangcheng is at the US embassy, complicating Sino-American relations just as Hillary Clinton arrives in Beijing for scheduled bilateral talks.