Authorities in the eastern Chinese province of Jiangsu have formally arrested a prominent rights activist after he visited the grave of executed Mao-era dissident Lin Zhao. Zhu Chengzhi has been incommunicado since Apr. 29 when he was taken away from the Lingyan Shan hillside cemetery on the outskirts of Suzhou, alongside fellow activists who laid wreaths to mark the anniversary of Lin's execution for alleged counterrevolutionary crimes under the rule of late supreme leader Mao Zedong. Suzhou authorities issued notification of Zhu's formal arrest to family members on Monday, stating that he was formally arrested on Nov. 12 on suspicion of "picking quarrels and stirring up trouble." He is currently being held in the Suzhou No. 1 Detention Center. "It's pretty unfathomable," Zhu's wife, who declined to be named, told RFA on Tuesday. "We have already hired a lawyer." "Why are they charging him with picking quarrels and stirring up trouble? I don't understand the government's policy on this," she said. "It's always hard to say what's going on with the government." But she declined to comment further. Pressure to confess Hunan-based activist Chen Siming said Zhu's wife may have made certain promises to the state security police. "For example, the state security police could have warned her not to make any public statements during the period of his residential surveillance," he said. "Maybe they want her to do ideological work with Zhu Chengzhi ... and that they promised to release him once she has done that." "She's not keen to be in touch with[fellow activists], and we can understand that, but I don't think her methods are exactly right," he said. Chen said the authorities are likely using Zhu's wife to put pressure on him to "confess," thereby enabling his release. But he said that outcome seems unlikely. "He was the most influential among those of us who went to commemorate Lin Zhao," Chen said. "He was the one who held out the longest, and the state security police wanted to send out a warning message by making an example of him for stability maintenance purposes." "It didn't occur to them that Zhu Chengzhi would refuse to capitulate or cooperate with police," he said. "Actually, all he would have to do would be to sign a letter promising not to commemorate Lin Zhao next year, and they'd let him out." Chen said Zhu now looks unlikely to avoid a criminal trial and prison sentence, unless he changes his mind. Prominent rights activist Zhu became one of China's most prominent rights activists after he spoke out about the death in police custody of labor rights activist Li Wangyang in 2013, and had previously been held on suspicion of subversion after he questioned the official verdict of suicide in Li's death. A Chinese police investigation into Li's death in June 2013 upheld an earlier verdict of suicide, despite widespread public doubts about the claim that the severely disabled 62-year-old hanged himself. Lin Zhao, whose birth name was Peng Lingzhao, has long been a poignant symbol for Chinese dissidents and democracy activists, but she has since also become a focal point for the country's army of petitioners, ordinary people who pursue complaints against the ruling Chinese Communist Party through official channels. A writer who grew up near Nanjing, in the eastern province of Jiangsu, Lin was a star student at the prestigious Beijing University's Chinese language department in the 1950s before being branded a "rightist" and a "class enemy" in 1957 for her criticism of then-supreme leader Mao Zedong's Anti-Rightist Movement targeting intellectuals. She was executed by firing squad at Shanghai's Longhua Airport in 1968 at the age of 36 after her sentence was changed to the death penalty because she refused to plead guilty.