Chinese authorities are holding the head of a human rights group after she supported a number of prominent dissidents and rights lawyers, RFA has learned. Xu Qin, who heads the China Human Rights Observer website founded by detained veteran pro-democracy activist Qin Yongmin, has been incommunicado since last week, fellow activists said. "Her friends where she lives told me that she is being held under criminal detention ... although they haven't seen any written notification yet," rights activist Chai Jinyuan told RFA. "I heard that she was discussing the possibility of going to visit[Qin Yongmin's wife] Zhao Suli on a fairly secure app," Chai said. "Since then, we haven't heard anything from her." Zhao was detained alongside Qin in January 2015, and both were initially held in unknown locations. But while Qin has since been tracked down by friends and lawyers to a detention center in the central city of Wuhan, Zhao had been in an unknown location for nearly three years, before resurfacing last week in the city's Peace Park, where she was allowed to spend time with relatives and call her son in the eastern province of Anhui. Sources say Zhao's reappearance is likely linked to Qin's subversion trial, for which no firm date has yet been announced. Chai added: "We're not sure exactly which day she went incommunicado, which day exactly she was detained, but nobody has been in touch with her for the past few days, and none of her family knows what has happened to her; either that, or they don't want to talk about it." "She isn't at liberty' Fellow rights activist Yuan Xiaohua said Xu is definitely not free. "I think we can be sure with no shadow of a doubt that she isn't at liberty right now," Yuan said. "Xu Qin has done so much for human rights in China, and recently was passionately involved in supporting two causes: She started the petition in support of[detained human rights lawyer] Yu Wensheng, and she collected funds for the relatives of Xu Lin." Singer-songwriter Xu Lin is currently being held by police in the Nansha Detention Center in the southern province of Guangdong on suspicion of "picking quarrels and stirring up trouble" after he penned a song in memory of Nobel peace laureate and political prisoner Liu Xiaobo, who died in police custody of late-stage liver cancer in July 2017. Yuan said he isn't optimistic about Xu's fate. "I think they really are going to arrest her," he said. "I think it's a question of retaliation for a lot of different things, and things don't look good for her right now." Xu last spoke to RFA on Feb. 8, reacting angrily to subversion charges against outspoken Nanjing journalist Sun Lin. She said at the time that she had been placed under close surveillance, preventing her from traveling to Nanjing for his trial. Calls to Xu's cell phone rang unanswered on Tuesday.