More than 10 days after Beijing and Washington reached a tentative agreement on his departure, Chen Guangcheng remains confined to a hospital bed as China seeks to show it controls the blind activist's fate.

Analysts say Beijing will not now go back on its commitment to allow the 40-year-old legal campaigner to go to the United States with his wife and children, after telling US officials it would expedite his travel documents.

But two weeks after he left the US embassy, where he had sought protection after fleeing from house arrest, the self-taught lawyer has still not been given a passport, or any indication of when he and his family can leave China.

He is a virtual prisoner at the central Beijing hospital where he is being treated for a broken foot sustained during his escape, unable to leave, and with friends, US diplomats and the media refused access to him.

Government officials who visited him last week said they would help him get a passport, but since then, he has heard nothing.

"The government officials have not come (for a week)," Chen told AFP this week by telephone from his hospital room. "I don't know why they are stalling, it is probably a face-saving tactic."

China expert Jean-Philippe Beja said Beijing was "allowing things to drag, showing that it is in control" of the situation, while also adopting a "fairly classic bureaucratic attitude."

Chen, who won plaudits for exposing rights abuses including forced sterilisations and late-term abortions, triggered a diplomatic crisis when he was smuggled into the US embassy last month in a high-stakes manoeuvre after clambering over several walls under cover of darkness to flee his guards.

His dramatic flight came just days before US Secretary of State Hillary Clinton arrived in Beijing for pre-arranged talks, and made headlines around the world, causing major embarrassment for the Chinese government.

By the time Clinton left on May 5, the affair appeared to have been settled.

State Department spokeswoman Victoria Nuland said Beijing had agreed to process Chen's travel documents "expeditiously," to allow him to take up an offer of a fellowship at New York University.

"Not allowing Chen to leave immediately is China's way of showing that it is in charge, and of regaining some of the lost face," said Alice Ekman, a China researcher at the Paris-based French Institute for International Relations.

"It's not in China's interest for Chen to remain on its territory," she added, pointing out that Chinese dissidents who go into exile generally find they have less of a voice.

For now, Chen's voice is still being heard. In a live telephone call to a hearing of the US Congress on Tuesday -- his second this month -- Chen accused Chinese authorities of a pattern of abuse against his extended family.

He said a charge of intentional homicide levelled against his nephew, after he attacked a local official who broke into his family's home after discovering Chen's escape, was motivated by revenge. The official survived the attack.

Lawmakers at the Congress hearing called for persistent pressure on China to allow the family to leave, as Nuland said US visas were ready for Chen, his wife and their two children.

"They (China) have publicly given their word. It would be very serious to go back on that," said Beja, of the French National Centre for Scientific Research.

Senior Human Rights Watch researcher Nicholas Bequelin said the delay might be because China's public security ministry, which handles the issuing of passports, opposed the deal between the Chinese and US foreign ministries on Chen's departure.

He said it was also possible that "no one is willing to take responsibility for giving passports to Chen and his family without clear, written instructions," meaning the green light would have to come from top leaders.

Analysts said the case was further complicated by a bitter battle for control between those who favour a hardline approach to dissent in China and those pushing for more openness, ahead of a 10-yearly leadership handover.

But Chen's departure "may be hastened by a calculation in Beijing that his continued presence in China is more damaging politically than his departure under US pressure," said Bequelin.

The other key question, analysts say, is whether Beijing will allow Chen to to return to China after a period of study in the US, as he has said he would like to do.

No Chinese dissident who has gone into exile has yet been allowed back into China, and Ekman said the government would "probably not allow the return of a man whose very image could become the unifying symbol of a (protest) movement."