Police in China have detained a prominent Uighur academic and outspoken critic of government policy towards the mostly Muslim minority, his wife said on Thursday.

Ilham Tohti was taken to an unknown location by several dozen police on Wednesday along with his mother, his wife Guzaili Nu'er told AFP, adding that police had confiscated their mobile phones and computers.

Tohti, 45, is an economist at a university in Beijing and has been critical of China's policies towards Uighurs, who are concentrated in the far western region of Xinjiang, which is regularly hit by unrest.

Police did not carry out any legal procedures while forcibly detaining Tohti in front of his two young children, his wife said.

"I asked (the police) where they had taken him, but they didn't say a word," she said.

"It had a big impact on my kids, they have been upset and crying since last night, now I don't even have a mobile phone."

Police combed through the family house, confiscating several computers and other items including phones and academic writings, she said.

It was not clear what triggered the police action, but Tohti has recently expressed fears on his website and in interviews with foreign media about increased pressure on Uighurs following a deadly attack in Beijing's Tiananmen Square in October.

Officials blamed the attack on suspects from Xinjiang.

Tohti has been detained on a number of occasions in the past few years, including for more than a week in 2009 after his website ran reports on riots in Xinjiang which killed around 200 people.

His website, Uighurbiz, was offline on Thursday after it published a story about the detention.

Tohti, who lectures at at the Central University for Nationalities in Beijing, did not answer his personal phone on Thursday and Beijing police were not immediately available for comment.

The vast Xinjiang region, which borders central Asia, has been hit by a series of violent clashes in the past year, which have killed dozens and which China's government has sometimes blamed on "terrorists".

China heavily restricts reporting in Xinjiang and it is hard to obtain independent accounts of events in the area.