Prominent Chinese human rights activist Cao Shunli, detained in September for staging sit-ins at the country's foreign ministry, has died, a fellow dissident and one of her lawyers said on Friday, after she was denied medical treatment in detention.

Cao's death is likely to trigger an outcry from China's fledgling rights community and criticism from the West, which has expressed concern about her case.

Friends of human rights activist Cao Shunli outside an intensive care unit earlier this month. They were not allowed to go inside the hospital unit.

The news comes soon after the start of a session in Geneva of the U.N. Human Rights Council, a body to which China was elected amid controversy last November.

"On Sept 14 ... she was perfectly fine and going to Europe for a trip. Now she's gone. Cao Shunli's wishes were never accomplished," dissident Hu Jia said.