Family members of Li Shufen, the 17-year-old girl whose death late last month sparked violent protests over the weekend in Guizhou province, told reporters yesterday they were still waiting for the cause of her death.

Up to 30,000 people took part in the protest over the weekend, which was prompted by a controversial police report into the death of Li last month.

On Wednesday, a team of forensic scientists from Guiyang, the provincial capital conducted a third autopsy to check whether she was raped or not before jumping into the river during an outing with two men and a girl.

Holding his dead sister's photo before their wooden house in the mountains, Li Shuyong said he did not believe she had committed suicide by drowning herself in a river, as the local government had said.

"It's impossible - I saw injuries on her face," Li, who will graduate from senior high school this summer, told China Daily during an interview with his family yesterday afternoon.

"I knew the girl who was with my sister that night, but not the two men," he said.

Police have said that Li Shufen had gone for the June 21 outing at the riverside with a 21-year-old man surnamed Chen, an 18-year-old man surnamed Liu, and a 16-year-old girl surnamed Wang, after drinking alcohol.

The local government has not allowed interview requests with the two men and the girl.

A document submitted by the local government stated that Li was unhappy with life because her parents favored her elder brother.

However, Li Shufen's father, Li Xiuhua, did not agree.

"My son and daughter have both performed well in their schools and I treat them equally," he told reporters yesterday.

"I love them."

Li Shufen's remains were buried on Wednesday afternoon near her family home after the latest autopsy.

Unlike his son, Li had not wanted the authorities to dig up his daughter's remains for further tests to confirm her cause of death.

"I want her to rest in peace," the father of the girl said.