BEIJING - Chinese human rights activist Cao Shunli died on Friday after falling critically ill in police detention where she was at first denied treatment, a rights group and prominent dissident said.
The hospital informed her brother her condition had grown serious but despite his arriving within about an hour, "Cao Shunli had already died", Chinese Human Rights Defenders (CHRD), a US-based advocacy group, reported online.
Cao joined a rare protest outside China's foreign ministry in June last year to demand greater participation in the UN's review of human rights in China, according to the Amnesty International and other rights groups.
She was set to travel to Switzerland for a UN Human Rights Council review last September but police detained her at Beijing's international airport, her lawyer Wang Yu told AFP earlier.
She became seriously ill and her condition was worsened after she was refused medical care, he said.
According to CHRD, she fell unconscious after suffering organ failure in late February.
Beijing-based dissident Hu Jia mentioned the news on his Twitter account, citing Cao's lawyer.
"The Communist Party should take full responsibility for her death," he wrote.
China's ruling party maintains a close grip on power, and new leaders who took over in late-2012 have detained dozens of dissidents and tightened control over social media, a growing forum for public discourse.
China won a seat on the UN Human Rights Council in November along with Russia, Saudi Arabia and Cuba, despite fierce international criticism of their records.
European countries and the US regularly condemn China on human rights, citing cases including its jailing of dissidents.
Beijing argues that its citizens enjoy increasing freedoms thanks to decades of rising prosperity.