International rights groups, lawyers' associations and democratic parties have hit out at China's jailing of human rights attorney Wang Quanzhang, calling for his immediate acquittal and release. Wang was handed a four-and-a-half year jail term on Monday by the Tianjin No. 2 Intermediate People's Court, which found him guilty of "subversion of state power." The verdict and sentence followed repeated delays resulting in Wang being held in pretrial detention of more than three years, with no access to a lawyer or family visits. "We strongly condemn the conviction and sentence on lawyer Wang Quanzhang by the Court," the Hong Kong-based Chinese Human Rights Lawyers Concern Group (CHRLCG) said in a statement co-signed by 30 organizations around the world, including the Geneva Bar Association and The Bar Human Rights Committee of England and Wales. "Since he was taken away by the police on Aug. 3, 2015, he has been denied the access to his family and family-appointed defense lawyers," the statement, which was also signed by Hong Kong democratic politicians and parties, including the Civic Party, Democratic Party and Demosisto, said. Dozens of activists marched to the ruling Chinese Communist Party's liaison office in Hong Kong on Tuesday to protest against Wang's jailing, chanting "There is no crime in defending our rights!" Rights attorney and campaigner Albert Ho said Hong Kong activists would continue to campaign for Wang's release. "None of these lawyers detained since July 2015, or the other people who have been locked up for something they said or expressed in a peaceful manner, should have to spend a single day in prison," Ho said. "We have a responsibility to speak out on behalf of these oppressed people." Concerns about mistreatment of Wang The CHRLCG statement said there are concerns that Wang may have been subjected to torture or other mistreatment in detention. "He has been detained incommunicado, during which he was reportedly tortured and suffered ill-treatment," it said. "We express grave concern over lawyer Wang's personal safety and health condition." During that time, the authorities failed to provide a proper account of Wang's prolonged detention to the public, including Wang's family and family-appointed defense lawyers, the statement said. The trial was held on Dec. 26 behind closed doors, with officials claiming that state secrets were involved in the case. "We maintain that the Chinese government, having imposed a prolonged incommunicado detention on lawyer Wang, has seriously infringed human rights, domestic law and international treaties ... including the International Covenant on Civil and Political Rights," the statement said. The statement said the claim that state secrets were involved was likely an abuse of national security provisions enabling closed trials, citing the "Johannesburg Principles" as saying that potential harm done by an open trial should threaten the existence or territorial integrity of a country before it a closed trial can be justified. The statement also hit out at the unilateral appointment by the authorities of Liu Weiguo as Wang's defense lawyer, disregarding Wang's right to hire lawyers chosen by him or his family. The overseas-based Chinese Human Rights Defenders (CHRD) network also hit out at Wang's jailing. "The case against Wang is centred on his legitimate activities in exercising his human rights and defending his clients' legal rights," the group said. "Authorities subjected Wang to months of enforced disappearance ... reportedly tortured him with electric shocks during interrogations, and denied him all access to lawyers of his own choice and cut off all communication with his family." It called on the governments, the E.U., the U.N., bar associations, law firms doing business in China, and law schools with exchange programs with Chinese universities to express serious concerns about the grave injustice involved in the imprisonment of Wang Quanzhang and other human rights lawyers.