A human rights activist nicknamed "Super Vulgar Butcher' has been jailed in China for eight years for "subversion" - the harshest sentence given in a crackdown on activists that began in the country in 2015. Wu Gan, a 44 year-old administrator at a Beijing law firm, campaigns for victims in criminal cases viewed as sensitive by authorities. He was sentenced at the Tianjin No 2 Intermediate People's Court. It is the longest sentence given so far in the "709 crackdown,' a sweep-up of hundreds of activists and lawyers that began two years ago. Mr Wu was accused of attempting to overthrow the ruling communist party. He used the name "Super Vulgar Butcher' on social media, and raised awareness of cases involving members of the public caught up in legal cases against officials. In 2009 he supported a pedicurist charged with killing a government official who attempted to molest her. He also campaigned for justice for the family of Xu Chunhe, who was killed by a police officer in the northeastern Heilongjiang province in 2015. Mr Wu claimed that he had been tortured while detained and refused to appear on state media television, which human rights groups say is often used to broadcast forced confessions from suspects. He said his trial in the government-controlled court was "meaningless". Amnesty International called the trial, which began last August, a "cruel farce", adding that it was "inconceivable that he will receive a fair hearing in what is a politically motivated prosecution." Mr Wu has remained unrepentant in his refusal to coorperate with authorities. "I knew I would be heavily sentenced but I will never regret my actions nor the choice I made today," he said when the trial began. It came as another lawyer also charged in the crackdown, Xie Yang, was found guilty of "subversion". He had represented citizens who had sued local governments. Mr Xie was told that he will not be jailed after he denied he was tortured while in custody, despite previously claiming he had been. Reading from a handwritten script in Changsha, in the southern Hunan province, he thanked the court for "lenient treatment". Amnesty International said: "Carrying out unfair trials and politicised sentencing of human rights defenders at the very time when diplomats, journalists, international observers and the general public are less likely to be able to respond reeks of a cynical political calculation."