BEIJING - AN OUTSPOKEN Chinese human rights lawyer went missing two weeks ago, several international rights groups said on Tuesday, expressing fears for his safety.

Gao Zhisheng, who has described being tortured in the past, disappeared Jan 19 and is believed to be detained by security officials at an unknown location, Amnesty International, Human Rights Watch and Human Rights in China wrote in a joint letter urging his release.

'We are intensely fearful for Gao Zhisheng's safety at this time, given the security authorities' long history of abusing him and his family,' said Sophie Richardson, Asia advocacy director at Human Rights Watch.

China has long been criticised for its violations of freedom of speech and religion and brutal repression of critics, and the UN Human Rights Council is set to review its record starting on Monday.

Mr Gao, an attorney, has tackled cases involving property-rights violations, the banned Falungong spiritual movement and religious persecution from 2002-2006.

He was arrested in August 2006, convicted at a one-day trial and placed under house arrest. He was accused of subversion on the basis of nine articles posted on foreign websites, state media reported at the time.

In September 2007, he was again detained for several weeks after sending an open letter to the US Congress denouncing China's human rights situation and detailing his and his family's harsh treatment by security forces.

He graphically described torture sessions including severe beatings, electric shock to his genitals, and cigarettes held to his eyes.

Last November, the UN Committee Against Torture issued a report on China saying that it remained 'deeply concerned about the continued allegations, corroborated by numerous Chinese legal sources, of routine and widespread use of torture and ill-treatment of suspects in police custody.' -- AP