The United Nations has urged China to better safeguard constitutionally protected rights and criticised Beijing for arbitrarily jailing those who peacefully voice religious and political views.
In a report on a September visit by the UN High Commission for Human Rights, the working group on arbitrary detention also condemned China for jailing citizens without trial through its "re-education through labor" system.
The report also lamented China's widespread use of vaguely defined terms in its criminal law, such as "disrupting social order" and "endangering national security" to imprison citizens for political purposes.
"Definitions in criminal law legislation having such vague, imprecise or sweeping elements ... shall not be used to punish the peaceful expression of the rights and freedoms that the Declaration of Human Rights grants to everyone," the report urged.
"Persons charged often invoke their freedom of opinion, expression, religion or belief, freedom of association or assembly, or the right to take part in the conduct of public affairs of the country as a legal basis for their conduct and exempting them from criminal responsibility," it said.
The working group called on China to give "proper weight to the rights of the individual" in such cases and better protect such fundamental rights guaranteed by the country's own constitution.
Posted on the UNHCHR website, the report said official interference in the September visit to the notorious Drachpi prison in Lhasa, the capital of Tibet was unacceptable.
UN investigators were told that prison regulations prohibited certain prisoners from being interviewed by "foreigners."
"The working group wishes to express its dissatisfaction with regard to this incident," it said.
"It is unacceptable that a (UN) Member State should impose limitations on human rights mechanisms under the pretext that their members are 'foreigners'." China has been widely accused of rampant rights violations in Tibet, where Tibetan religious figures are routinely jailed for voicing opposition to Chinese rule in the region.
The visit was the second by the working group to China, following an earlier visit in 1996 which came to many of the same conclusions.