Lawyers have filed petitions urging the UN to press China to release Nobel Peace Prize winner Liu Xiaobo from prison and free his wife from house arrest, a report said on Friday.
A team of international lawyers filed an "urgent action petition" with the UN Working Group on Arbitrary Detention Thursday, asking it to rule that the detentions violate international law, the Washington-based rights group Freedom Now, which is coordinating the legal team, said in a statement.
Liu Xiaobo was arrested in December 2008, two days before the release of the Charter '08 for democratic reform. Liu was later sentenced to 11 years in prison for subversion, for his role in organising the charter.
Chinese authorities have kept his wife, Liu Xia, under house arrest and cut off her two mobile phone numbers since the award of the Nobel Prize on October 8.
"The Chinese government's imprisonment of Liu Xiaobo violates the Chinese constitution and international law, and the ongoing house arrest of Liu Xia shocks the conscience," Maran Turner, the executive director of Freedom Now said.
"We urge the Chinese government to immediately release both Liu Xiaobo and Liu Xia from their illegal and unjust detentions," Turner said.
The petitions follow a succession of calls by international rights groups and politicians for China to release Liu Xiaobo.
Fifteen fellow Nobel Peace Prize laureates have issued an open letter to UN Secretary-General Ban Ki-moon and leaders of the Group of 20 nations asking them to press Chinese President Hu Jintao during next week's G20 summit in Seoul to release Liu Xiaobo and Liu Xia.
Dozens of prominent Chinese activists have been questioned, placed under house arrest or disappeared since the awarded of the prize.
Human rights observers expect the government's crackdown on dissidents to continue at least until after the Nobel Peace Prize award ceremony in Oslo December 10.