Beijing - His name was familiar to US President George W Bush and Chinese President Hu Jintao months before he won the EU's Sakharov prize for human rights, yet just a few years ago China's most prominent dissident was a largely unknown activist for the rights of people living with HIV/AIDS.

Hu Jia's international reputation grew while he was forced to spend most of his time confined inside his suburban apartment on the outskirts of Beijing in 2006 and 2007.

Before his formal arrest in late December, Hu had spent most of the previous two years under virtual house arrest or other forms of detention.

With no paid employment and few visitors allowed, he used his enforced isolation to act as a bridge between foreign media and the growing number of rights activists across the country.

Each weekday, Hu collected and disseminated information on rights cases and other issues in China via the internet and telephone.

He also learned the names of many of the State Security officers who loitered outside his apartment every day.

Some of them remain stationed there to prevent his wife, fellow activist Zeng Jinyan, from speaking to foreign media and governments.

But Hu and Zeng did manage to testify by telephone to a European Parliamentary hearing on China's human rights record last November.

Hu's activism began in the late 1990s when the economics graduate volunteered to work on environmental projects.

In 2001, he began helping villagers infected with HIV/AIDS through blood-selling schemes in the central province of Henan.

The following year, Hu and four friends had their first run-in with state security police who intercepted them and seized film after they travelled to Henan villages.

The group took Christmas toys and clothes to children in poor villages that were decimated through AIDS spread by the illegal collection and sale of blood.

"It seemed like the worst scenes of AIDS in Africa, with old and young people infected," Hu said.

"State security police threatened us and said that AIDS was a state secret," he said.

Hu believes that China was "lucky" to be shaken out of its complacency on AIDS by the scandal over a cover-up of hundreds of cases of severe acute respiratory syndrome (SARS) in Beijing.

"After SARS in 2003, nobody dared to say that AIDS was a state secret any more," Hu said. "It gave us an opportunity to be more open."

His continued advocacy for the rights of people living with HIV/AIDS in China brought him international attention and several awards.

But after two "golden years" of relatively open activism, the climate began to change with the arrest and harassment of AIDS activists in 2005, he said.

His own surveillance became a little more relaxed after the birth of the couple's first child last November.

The Dalai Lama sent a Tibetan name for their daughter at their request, he said, in a move that can only have further angered the Chinese government.

Hu is a practising Tibetan Buddhist and Zeng met the Dalai Lama, Tibet's spiritual leader, in his Indian exile in 2006.

Hu and Zeng also released a short documentary last year about their surveillance, and excerpts are now widely available on the internet.

"A week after our wedding party, Hu Jia was put under house arrest by the State Security police and after a month he disappeared... and there was no news for 41 days," Zeng said at the start of the 30- minute film, "Prisoners of Freedom City."

The title of the documentary reflected the irony of the couple's restricted life in a modern, low-rise estate known as BOBO Freedom City.

Hu said he was seized by state security police from the party's Central Political and Judiciary Committee and taken to a secret site, where he was detained for 41 days in February and March 2006.

"They tied my hands behind my back, pushed me to the floor (of their car) and put a black bag over my head," he said. "It was just like a kidnapping by the mafia."

He believed the arrest was linked to his support for rights lawyer Gao Zhisheng, who was convicted of subversion in December 2006 but given a suspended prison sentence.

Hu and Gao, who is believed to be held under house arrest at a secret location in Beijing, were both nominated for this year's Nobel Peace Prize.

Hu said that during his own house arrest he was constantly expecting the fateful knock on the door that would mean the authorities had decided to press charges against him.

That knock came just 18 days after Hu's interview with Deutsche Presse-Agentur dpa.

Despite appeals from the European Union, the United States and rights groups for his release, a Beijing court sentenced Hu to three and a half years in prison in March for "inciting subversion of state power". (dpa)