BEIJING (AFP) - China rejected on Monday criticism from the United Nations over the detention of a Chinese human rights lawyer, calling it an interference in the country's domestic affairs.

The UN High Commissioner for Human Rights said on Friday that it was "deeply troubled" by last Wednesday's detention of Chen Jiangang, a vocal civil rights defender, and his family during a vacation.

"We are dismayed by this continuing pattern of harassment of lawyers, through continued detention, without full due process guarantees and with alleged exposure to ill-treatment," the UN office added. 

Foreign ministry spokesman Geng Shuang responded on Monday saying that the UN agency's statement "disregards objectivity and constitutes an interference in China domestic affairs and judicial sovereignty".

Beijing has come under increased fire from the international community as it tightens the screws on the country's civil society in a clampdown that is said to have relied on torture and illegal detentions to punish critics of the government.

While the government initially targeted political activists and human rights campaigners, it has increasingly turned its attention to lawyers who represent them.

Chen's family was released on Thursday morning and permitted to fly back to Beijing.

But Chen was forced to drive 3,200-kilometre (2,000-mile) back with three police escorts, according to Amnesty International. 

Chen told AFP in a text message on Monday that he was still on the road, driving through Taiyuan County in Shanxi province, about five hours from Beijing. 

Chen was a former defence lawyer for Xie Yang, who was detained during the "709 crackdown" in the summer of 2015, when authorities rounded up some 200 legal staff and activists.

Chen remained vocal on Xie's case, drawing attention to his former client's allegations of torture in police custody, even after a court in the central city of Changsha denied Xie his pick of defence and provided court-appointed lawyers instead.

Xie pleaded guilty on Monday to charges of "inciting subversion of state power and disrupting court order". His sentencing date was not announced.