A women's legal aid centre shut down in Beijing was probably ordered to close because it took money from overseas donors, state media said Tuesday after US presidential hopeful Hilary Clinton backed its founder.

Beijing police ordered the closure of the Zhongze Women's Legal Counselling and Service Centre, which represented low income Chinese women free of charge, the state-run Global Times said.

"The (police) request may have resulted from funds that came from overseas organisations," it said, adding that the centre received funding from the US-based Ford Foundation.

The article comes as charity workers in China report increased police pressure about foreign funding, and as state-run media accuse overseas organisations of plotting to undermine the country's authoritarian political system.

China last month detained and expelled a Swedish human rights activist who had aided Chinese lawyers, after parading him on state television confessing to breaking the law.

The Zhongze centre, founded by lawyer Guo Jianmei after a high-profile United Nations conference on women held in Beijing in 1995, was seen as symbolising an emerging civil society in China attempting to use courts to challenge injustice.

It said in a statement on its website that it was closing as of Monday, thanking supporters without giving an explanation.

Potential Democratic presidential nominee Hilary Clinton, who attended the conference, said on Twitter: "True in Beijing in 1995, true today: Women's rights are human rights. This center should remain-I stand with Guo."

Under President Xi Jinping, China's ruling Communist party under has reasserted controls over civil society, detaining more than 130 human rights lawyers and legal staff in the past year.

Beijing is preparing a new law which according to drafts would give police tighter controls over foreign non-governmental organisations (NGOs).

In an op-ed, the Global Times said the centre's willingness to "take on sensitive cases and take foreign funds provides a perspective on this issue".

The editorial, attributed to Shan Renping, a penname for the paper's editor Hu Xijin, added that foreign aid "had a political slant and selectivity which could disturb Chinese society."

The Zhongze centre was renowned for defending Deng Yujiao, who in 2009 stabbed a government official to death after he attempted to sexually assault her. Public pressure led prosecutors to reduce the original charge of murder to the lesser "intentional assault".