Critics have assailed the contention that Mr. Li killed himself, saying his poor health — he was almost entirely blind, deaf and physically weak — made it unlikely that he could orchestrate his own hanging. They also questioned how he carried out the suicide given the presence of police minders outside his hospital room.

Commissioned by the Hunan Province Public Security Bureau in response to the public uproar over Mr. Li’s death, the report cited “experts” who reviewed surveillance video and determined that only nurses, caregivers and his roommates had entered Mr. Li’s room in the hours before his body was found hanging from a window.

It also said that Mr. Li’s body bore no signs of trauma and that a forensic investigation had determined he died from hanging — a rebuttal to those who cited a post-mortem photograph, widely circulated on the Internet, that appeared to show Mr. Li’s feet touching the ground. “People have been hanged in positions that include standing, sitting or even lying down,” the report said.

It is unclear how much credence Mr. Li’s family and supporters in Hunan put in the inquiry’s findings because they have been kept incommunicado by the police. On Friday, the cellphones of his sister, brother-in-law and a half-dozen friends were turned off; last month, several said they were under police surveillance and had been instructed not to talk to the news media.