Prominent Chinese anti-corruption campaigner Xu Zhiyong was on Sunday ordered jailed for four years after a court found him guilty of "disrupting public order" in a conviction seen as punishment for his efforts to expose high-level graft within President Xi Jinping's government. Xu is China's most highest profile dissident to be sentenced to jail since 2009, when Nobel laureate Liu Xiaobo was ordered imprisoned for 11 years for subversion after helping organize the "Charter 08" petition urging the overthrow of one-party rule. Also on Sunday, another top Chinese dissident Hu Jia, who had demanded officials to publicly disclose their assets, was detained by police on a charge of "suspicion of causing a disturbance" after he spoke to RFA's Mandarin Service on Xu's jailing. Xu's conviction came four days after a U.S.-based journalism group released a report linking relatives of President Xi and other leaders of the ruling Chinese Communist Party to an intricate network of thousands of offshore companies in tax havens that allegedly helped shroud the Communist elite's wealth. Xu, who has been detained by Chinese authorities since July last year, was found guilty of "gathering a crowd to disturb public order," the Beijing No. 1 Intermediate People's Court said on its official microblog. Xu and several other members of his "New Citizens' Movement" had staged peaceful protests for asset disclosure by officials and campaigned for the rights of children from rural areas to be educated in cities. The verdict on Xu was announced amid tight security as hundreds of police stationed around the court kept foreign journalists at bay and briefly detained Xu's lawyer Zhang Qingfang after he denounced the court process as "totally unjust and unacceptable." "What remained of the respect for rule of law in China has been completely destroyed today," Zhang told RFA. "It is unacceptable to jail a man who has been a longtime staunch promoter for social progress." Appeal Zhang said he would appeal against the court ruling although he said he did not expect a favorable decision, adding that he would meet with Xu on Monday when several other New Citizens Movement members are scheduled to stand trial. "Appealing will not change the outcome," he said. "However, as other co-defendants have not yet been tried and if we do not appeal, this ruling will go into effect[against others]." Zhang said the government wanted to use Xu's conviction to scare off other activists. "The authorities want to use it to tell rights activists that, "You should not cross the red line set by the government. If you do, Xu Zhiyong's jailing sets a precedent for you.'" Xu's long time friend, Beijing-based human rights advocate Hu Jia said before he was detained Sunday that the Chinese people's struggle for freedom and democracy would not be shaken be the conviction. "If the Chinese people fear tyranny, China would still be under the Qin dynasty," he told RFA, referring referring to the harsh rule of emperor Qin Shi Huang from 259 to 210 B.C. "Thus the despotic measures taken by the current Chinese authorities will only create more enemies[for the government]" and solidify the anti-government movement, he said. Hu Jia, who was jailed in 2008 for three and a half years on subversion charges for criticizing human rights restrictions, was taken away by the Beijing National Security Police on Sunday after the interview. 'Defiance' Hu's friend Li Xiaoling said Hu Jia might face charges of "defiance and provocation." Beijing-based rights lawyer Tang Jitian said "the authorities can no longer use terms such as "subversion' or "inciting subversion' to intimidate the people." Hu was seen by some of his supporters as a potential recipient of the Nobel Peace Prize before it went to Liu Xiaobo in 2010. Human Rights Watch said Xu's conviction and four-year sentence was a pretext to chill popular protests against corruption while another rights group Amnesty International called it a travesty. "The harsh sentence for a moderate critic who reflected widespread public concern about corruption shows just how little tolerance there is towards dissent in China today," said Brad Adams, Asia Director at Human Rights Watch. "Xi Jinping has made fighting corruption the linchpin of his presidency, but when an average citizen takes up the same cause, he is sent to prison. This hypocrisy makes a mockery of the president's anti-corruption campaign." 'Predictable verdict' Roseann Rife, East Asia Research Director at Amnesty International, said the action against Xu was "a shameful but sadly predictable verdict," adding that the Chinese authorities "have once again opted for the rule of fear over the rule of law." "At best the injustice of prosecuting Xu Zhiyong is hypocrisy of the highest order. On the surface his calls to expose corruption coincide with President Xi Jinping's own much heralded clampdown," Rife said. "But the message sent from the courtroom today runs far deeper: In Xi Jinping's China the Communist Party maintains a monopoly on the political process and anyone that speaks out will be severely dealt with." Western governments expressed concern over Beijing's action against Xu. The United States said it was "deeply disappointed" at the verdict, saying it is concerned that Xu's prosecution "is retribution for his public campaign to expose corruption and for the peaceful expression of his views." "We call on Chinese authorities to release Xu and other political prisoners immediately... and guarantee them the protections and freedoms to which they are entitled under China's international human rights commitments," State Department spokeswoman Jen Psaki said in a statement. European diplomats also called on Chinese authorities to release Xu immediately. Raphael Droszewski, first secretary of the European Union delegation to China, said the case has "heightened our concern at the situation being faced by a number of Chinese human rights defenders who have been prosecuted in relation to peaceful action against corruption and public advocacy of the law, transparency and social justice," the Associated Press reported. In a video message filmed secretly from behind bars at the Beijing No. 3 Detention Center after his detention, Xu said he is willing to take the consequences of his activism and called on others to do the same. More trials Chinese courts have tried two other activists in the New Citizens Movement in the past week, including Zhao Changqing, who was a student leader during 1989 pro-democracy protests at Tiananmen Square and previously served eight years in jail. Three others were tried in December but no verdict has yet been released. In total 20 to 40 people involved with the New Citizens Movement have been detained since last year, according to members. Last week, multimillionaire businessman Wang Gongquan,who backed the New Citizens Movement, was bailed after he apparently confessed to helping "organize and incite criminal activities", a Beijing court said in a statement.