Hong Kong (CNN) -- Friends of a high-profile Chinese dissident found dead in his hospital room Wednesday slammed official claims that he hanged himself as "insulting" and "ridiculous."
Huang Lihong told CNN that he had visited long-time labor rights activist Li Wangyang at Daxiang District Hospital in Shaoyang, Hunan province, a few days before his death on June 6.
"He was in good spirits... There was absolutely no sign showing he wanted to take his own life. He was also listening to my radio and told his sister to buy him one, too," Huang said.
Li was blind, deaf and had trouble walking after spending more than 20 years in prison following the Tiananmen Square crackdown in 1989. He was one of China's first labor rights activists and was jailed shortly after the June 4 massacre for urging workers to strike, according to Human Rights in China (HRIC).
After spending 11 years in jail, Li was released in 2000 only to be imprisoned again in 2001 for doggedly petitioning Shaoyang authorities to pay his medical expenses for injuries suffered through torture in prison.
They refused and he was sentenced to a further 10 years for "incitement to subvert state power," according to HRIC. He was released last May but his family said he had been under 24-hour police surveillance in hospital.
"It's unbelievable that he could hang himself. He's weak, couldn't really walk down from the second floor on his own," his friend Zhou Zhirong told CNN.
Friends described a man who was unwavering in his determination to fight for his beliefs.
"It's an insult to say someone like him killed himself this way," Huang said. "Li Wangyang said numerous times to me and others that he would keep fighting till the end of his life. He never quits. It's ridiculous even to think he would commit suicide and none of his friends or family believes what the police say now. He was killed by others for sure," he said.
Li's brother-in-law Zhao Baozhu told HRIC that hospital staff phoned him and his wife, Li's sister Li Wangling, just after 6 a.m. on June 6 to tell them that Li had committed suicide.
Zhao said they rushed to the hospital and found Li's body "hanging by the window." He noted that Li's feet were still on the ground.
"They [hospital staff] did not let us get near him, and did not let us take photos. Then they dragged his body away," HRIC said in statement on its website.
"I've never witnessed a suicide like this,"said Mi Ling Tsui, communications director at HRIC. "It raises questions. How do you hang yourself with your feet on the ground?"
Despite the family's claims that they weren't allowed to take photos, three images of Li said to have been taken after his death have been published on Boxun, a U.S.-based Chinese-language news website.
Two photos show Li standing by a window with a knotted sheet around his neck, apparently tied to bars on a window above. A third photo shows Li's feet firmly on the ground. He's still wearing slippers.
CNN tried repeatedly to contact Daxiang District Hospital where Li died but no one answered the phone. An official who answered the phone at the publicity office of Shaoyang Public Security Station said he hadn't heard of Li's case and advised calling another number. Attempts to call other government offices also failed.
It's not known how long Li had been in hospital before his death. HRIC said only that he was being treated for his "deteriorating health." Zhao told HRIC that authorities started monitoring Li on May 22.
Friends said the phones of Li's sister Li Wangling and brother-in-law Zhao Baozhu don't appear to be working. They say they believe the couple has been detained in a hotel near the hospital where Li died.
Earlier, Li's family and rights campaigners called for an immediate investigation and full autopsy to determine his cause of death.
"The Chinese authorities must thoroughly investigate the circumstances surrounding Li Wangyang's death and take seriously the claims made by his family and friends that this was not suicide," said Donna Guest, Asia Pacific Deputy Director at Amnesty International.
In the hours after Li's death, a petition appeared online urging his "suicide" to be investigated by authorities outside Shaoyang province and for the findings to be made public. It was started by Hong Kong-based journalist Bei Feng, Chinese economist Xia Yeliang and literary scholar Wu Renhua.
At the time of writing, more than 2,000 people had added their names, including many from who listed their locations China. Some entries written in Mandarin listed their location as "hell."
Liu Jiayi of Hong Kong wrote: "Comrade Li Wangyang, you perservered for more than 20 years, no one believes that you killed yourself! But now you can leave the domain of the Chinese Communist dictatorship. You are finally free! I wish you a good journey!"
Chen of Beijing wrote: "Independently investigate and track down the true murderers. Let the world know who persecuted and murdered Li Wangyang, and bring them to trial."
Li's name recently appeared in a list of "political prisoners" who had been detained as of the end of 2011 in the U.S. Country Reports on Human Rights Practices.
CNN's Shao Tian contributed to this report.