China rejected a United Nations watchdog's criticisms of its human rights record Thursday, with a spokeswoman calling it biased and "incorrect".

The UN Committee Against Torture report, released Wednesday, urged China to end the rampant use of torture in its prisons, close all "black jails" and halt a large-scale crackdown on lawyers and activists.

The report was not based on an "objective and fair view" of China and some contents were "based on incorrect information", said foreign ministry spokesperson Hua Chunying.

"Our position on opposing torture is firm and consistent and we believe that we will make greater efforts in this regard," she told a regular briefing in Beijing.

The UN report said more than 200 lawyers and activists had been rounded up in an "unprecedented" crackdown since July, with 25 more reportedly under residential surveillance, and four allegedly unaccounted for.

China's rebuttal came on International Human Rights Day, which saw both the US ambassador to China and the German embassy issue statements strongly condemning China's human rights behaviour.

"Throughout the past year, too many Chinese citizens were jailed merely for peacefully expressing their views," said US ambassador Max Baucus in a statement on the embassy website.

The statement cited several cases, including detained rights lawyer Pu Zhiqiang and Uighur economics professor Ilham Tohti who was last year convicted of separatism and jailed for life.

The German embassy statement -- which also named Pu and Tohti among several other examples -- said that "serious problems persist with regard to freedom of opinion".

The embassy urged China to "adhere to its international obligations for the protection of human rights".

Hua said that accusations of human rights abuses represented "political prejudice" and a "lopsided" point of view.

"It seems that some people always choose to play up these individual cases, and they intentionally ignore the general situation of human rights in China," she said.

The United States and Germany "should not interfere in China's judicial sovereignty" when it comes to Chinese citizens and "should focus on their own domestic situations", she added.

"We have found a development path that suits China's national conditions and China's human rights conditions," she said.

The UN report said that "the practice of torture and ill-treatment is still deeply entrenched in the criminal justice system" in China, and voiced alarm over a recent law change that legitimised secret detentions.

A report by Amnesty International last month detailed how suspects received electric shocks, were punched, kicked, hit with shoes or bottles filled with water, denied sleep and locked in iron chairs, forcing them into painful postures for hours on end.

Artist Ai Weiwei believes activism helping change China
Melbourne (AFP) Dec 10, 2015 - Dissident artist Ai Weiwei Thursday said he believes his activism is helping to change China and the price he has paid for speaking out was worth it.

Ai, in Melbourne for a new exhibition of his work at the National Gallery of Victoria, with human rights and politics at its core, said someone had to make the sacrifice and take a stand against injustice.

"Freedom of speech or human rights is never something you can grant for free," he told the Australian Broadcasting Corporation.

"It takes somebody to sacrifice, to make the effort. Yes, I have suffered and many people are continuously suffering. My lawyer is still in jail after a year-and-a-half. And many, many people are still in jail."

Ai, China's most prominent contemporary artist, was detained in 2011 for 81 days over his advocacy of democracy and human rights as well as other criticisms of the government in Beijing.

Following the 2011 detention, he was subsequently placed under house arrest and had his passport taken away. The document was only returned in July this year, enabling him to travel overseas.

Asked if his activism and art was changing China, he replied: "I think if I can change myself I can change China. I'm part of China and China is part of me. So, every day I try to do some change.

"I try to live up to my beliefs," he added to the broadcaster.

"I try to tell myself to pay more attention to other people's voices... and to build the weak voices, or the people who have no voice, to help them."

He said he was not worried that his public image was as much built on his activism as his art.

"It doesn't bother me at all," Ai said. "I care about human rights and freedom of speech. And I think that strongly protects the very essential meaning of art."

The world-first exhibition, Andy Warhol/Ai Weiwei, explores the mutual conceptual interests of the two artists.

More than 300 works are being presented, including rare and never-seen-before works by Warhol and new commissions by Ai.