“When Bo Xilai’s right-hand man, the police chief, showed up in a consulate asking for asylum, he did not fit any of the categories for the United States giving him asylum,” Clinton said. “He had a record of corruption, of thuggishness, brutality. He was an enforcer for Bo Xilai.”

Wang fled to the consulate after a violent exchange with Bo in Chongqing, where Bo was party boss. Wang had informed him that Bo’s wife was suspected in the murder of Neil Heywood, a British expat who had helped Bo’s son. Bo exploded in anger, slapping Wang across the face, and Wang left the city days later to seek US protection.

Wang was “trying to somehow get his way to a place of safety. But on the other hand, the consulate was quickly encircled by other police who were either subordinate to Bo Xilai or looking to curry favour. So it was becoming a very dangerous situation,” Clinton said.

Wang “kept saying that he wanted to get the truth to Beijing. He wanted the government in Beijing to know what was happening. So we said: ‘We can arrange that.’ So indeed that’s what we did. We were very discreet about it and did not try to embarrass anybody involved in it, but tried to handle it in a very professional manner, which I think we accomplished.”

Wang was sentenced to 15 years in jail and Bo was sentenced to life imprisonment in September but plans to appeal. Bo’s wife, Gu Kailai, was given a suspended death sentence last year.

Clinton also spoke about the assistance the US provided to blind legal activist Chen Guangcheng to help him leave the country.

Chen escaped house arrest in Shandong province and fled to the US embassy in Beijing at the end of April last year, one week before China was to host annual high-level talks with Washington.

“I get called late one night about Chen,” Clinton said. “It was about a week before our annual Strategic and Economic Dialogue meeting, this time in Beijing. I was very well aware that this would be an issue in the relationship. But I also believed that this was an example of American values in practice. This was a man who, yes, deserved American support and attention and protection,” she said.

“Then [we] had to tell the Chinese government that we were offering hospitality to one of their citizens and would love to talk to them about it,” Clinton said.

“I had to go to State Councillor Dai Bingguo and I had to say: ‘This is in your interests and it’s in our interests, and there’s got to be a way we can work this out.’ His first response was: ‘We never want to talk about this man again with anybody. We can’t go back into negotiations.’

“I said: ‘We have to, and we need to start now and we need to get this resolved by the end of our meetings.’”

Clinton said she took advice from her Chinese counterparts not to raise the matter in meetings with Hu Jintao, the former president, and Wen Jiabao, the former premier. But negotiations over Chen’s fate overshadowed the two-day annual talks.

It was initially agreed that Chen would be relocated to a safe place on the mainland and be free from official harassment. On May 2 last year, the six-day stand-off ended with US ambassador Gary Locke escorting Chen from the embassy to a hospital, where he was treated for injuries sustained during his escape from house arrest.

Clinton called Chen on his way to the hospital, and the two had what US officials described at the time as an emotional conversation.

The Foreign Ministry demanded that Washington apologise for meddling in China’s domestic affairs.

State media also angrily denounced Chen, whom they labelled a pawn of Western forces, and in reference to Locke warned that “diplomats should not exceed their roles”.

While in the hospital, Chen had a change of heart, saying Beijing had reneged on promises to safeguard his family and that he wanted to leave China.

The government announced that he could study abroad, and he boarded a flight to New York on May 19.