Police say a veteran activist found hanging in his hospital room committed suicide, dismissing allegations of foul play from his family and fellow activists who had used his death as a symbol of China's repression of government critics.

Li Wangyang died last month in central China, where his promotion of labor rights had led to more than 20 years of prison or hard labor.

Investigators found Li's fingerprints on the hospital window bar from which he was found hanging, said a police report released through the Hong Kong China News Agency late Thursday. It said an autopsy concluded Li's injuries were consistent with suicide and found no signs of bruising, organ damage or other evidence of struggle.

People seen in hospital surveillance video taken in the hall outside his room around the time of his death were all staff or other patients' visitors, said the Hunan Public Security Bureau report.

Relatives say the 62-year-old labor rights activist never talked about killing himself despite his prison time and being very sick from heart disease and diabetes. Supporters say it was suspicious Li was found hanging by his neck even though his feet touched the ground.

Li's brother-in-law, Zhao Baozhu, said last month that the activist had never expressed a desire to hurt himself and had appeared normal over dinner the night before he died. Zhao didn't make any allegation as to who could have been behind Li's death.

Li had advocated for independent labor unions in central China's Hunan province and was caught in the sweeping nationwide crackdown on all forms of dissent after the Tiananmen Square democracy protests were quashed in 1989. He was convicted of "counterrevolutionary propaganda and incitement" and spent much of his 11-year sentence doing hard labor. At times, he was held in solitary confinement and beaten so badly that he had to be hospitalized, according to Human Rights in China.

Li was subsequently sentenced to 10 years' imprisonment for inciting subversion after demanding government help for health problems caused by beatings and mistreatment in prison.

His death came two days after the 23rd anniversary of the June 4 Tiananmen crackdown and shortly before the 15th anniversary of Hong Kong's return to Beijing's control. Activists in the semiautonomous territory rallied strongly around Li's death, seeing him as a symbol of Chinese repression and a warning against allowing China to erode Hong Kong's civil liberties.

Hong Kong supporters wrote letters to Chinese President Hu Jintao demanding a thorough investigation into Li's death.

Activists in China voiced similar outrage on microblog sites, though Li's name was quickly blocked by government censors.

Calls to city officials and police departments in Hunan's Shaoyang city, where Li was found dead, rang unanswered Friday. The mobile phone of Li's brother-in-law was switched off.