Hong Kong - Hong Kong was Monday accused of handing over a former Tiananmen Square dissident to mainland Chinese police, leading to his arrest and detention on fraud charges.

Zhou Yongjun, 42, a student leader in the 1989 pro-democracy movement who is now in the process of becoming a US citizen, has been held in China for almost a year after being arrested in Hong Kong.

At a press conference Monday, his girlfriend and mother of his young daughter accused the Hong Kong government of sending Zhou to China where he is detained in Sichuan.

His lawyer told the press conference that Zhou, who was jailed after the 1989 demonstrations and then left China for the US, had been tortured and denied family visits since his arrest last year.

Zhou came to Hong Kong with the intention of visiting his elderly parents in China using a Malaysian national's passport last September. He has no Chinese visa since fleeing to the US.

Girlfriend Zhang Yuewei said Zhou's family only learned of his arrest and detention in Sichuan seven months after he was placed in custody in mainland China.

Zhou, one of the most prominent of the 1989 student demonstrators, was pictured kneeling on the steps of the Great Hall of the People during the Tiananmen Square protests pleading for political reforms.

Pro-democracy Hong Kong legislator Albert Ho accused the city government of "totally disregarding" their legal obligations to Zhou by handing him over to China.

There was no immediate response from the government of Hong Kong, which reverted to Chinese sovereignty from Britain in 1997 under a "one country, two systems" agreement.

The city has a separate legal and political system and a mini-constitution that guarantees freedom of speech and political freedoms. Extraditions to China are rare.

Zhou is said to face charges including defrauding the Hang Seng Bank, accusations believed to relate to his use of a bogus identity to attempt to enter China.

His girlfriend and lawyer said there is a political motive for trying him in Sichuan rather than in Hong Kong where the alleged offences took place.

Hundreds, possibly thousands, of students were killed by Chinese troops in a brutal crushing of the pro-democracy movement in the streets around Tiananmen Square in June 1989. (dpa)