Bo Xilai, the charismatic but controversial Communist Party secretary of Chongqing, waits for a question from the media during a press conference at the Great Hall of the People in Beijing on Friday. (STR/AFP/GETTY IMAGES)

— Bo Xilai, the colorful yet controversial Communist Party chief whose political fortunes have been the subject of fervent speculation, said Friday he was not under investigation and denied having offered to resign after his longtime right-hand man was detained as part of a reported corruption probe.

Bo, the Communist Party boss in the sprawling south-central municipality of Chongqing, said he was as surprised as anyone when his aide, Wang Lijun, who was the vice-mayor and former police chief, sought refuge Feb. 6 at the U.S. consulate in neighboring Chengdu. Wang was either seeking to defect, or trying to hide out from Chongqing authorities in fear of his life, depending on which version of the bizarre episode is believed.

“I truly never expected this to happen,” said Bo, speaking to reporters at a meeting of the Chongqing delegation during the annual session of China’s legislature, the National People’s Congress. “I felt it was extremely sudden.”

Bo has long been considered a top contender for a promotion this year to the powerful nine-member Politburo Standing Committee, but the episode involving Wang — who is now believed being held incommunicado in Beijing — may have jeopardized Bo’s ambitions.

In the absence of any real information on Wang, the Internet rumor mill, and Hong Kong newspapers, have been filled with speculation that the case may have been stoked by Bo’s political rivals as a way to embarrass him in advance of the scheduled leadership reshuffle at the 18th Party Congress this fall.

The mystery only deepened this week, first when a Chongqing businessman, Li Jun, now in hiding outside of China, detailed to The Washington Post and the Financial Times a story of being harassed, jailed and forced to flee the country in a property dispute with Chongqing’s power-brokers, including Wang Lijun.

Then on Thursday, Zhang Mingyu, a Chongqing property developer, was reported detained here in Beijing, after he publicly threatened to provide more details on the Wang Lijun case.

Bo, looking tired while speaking to reporters Friday, tried to brush off the case and questions about its impact on his own plans.

“For myself, speaking from my heart, I’ve never associated myself with anything specific about the 18th Congress,” Bo said. Speaking of his rumored offer to quit, he said, "That's totally a rumor, totally imaginary. There's no such thing as a resignation."

“Wang Lijun is now being investigated by the relevant central agencies,” Bo said. “When the results are concluded, they will be released to everyone.”

While the annual legislative conclave is largely a ceremonial and scripted affair — with government proposals being mostly rubber-stamped after some pro forma discussion — the upcoming leadership changes, and the mystery surrounding Wang, have this year provided a backdrop of intrigue.

Also, this year’s gathering, which brings together the top Party leadership from around the country, offered a fascinating study in contrasting styles, as analysts of China’s secretive politics tried to glean clues about the upcoming leadership change from the subtlest of signs.

For example, analysts were trying to dissect the meaning behind an appearance by Zhou Yongkang, the top Politburo Standing Committee member in charge of public security, at a meeting of the Chongqing delegation on Thursday. Images of Zhou seated next to Bo were broadcast on the main CCTV news channels, leading to speculation that Zhou was giving Bo a public sign of support.

Also, while Bo appeared tired and defensive, the man considered his chief rival for promotion to the Standing Committee — the Guangdong Party chief Wang Yang — met the press on March 5 and cheerfully bantered with reporters on topics like the recent uprising by villagers in the fishing hamlet of Wukan. Wang said the resolution of the Wukan case, in which the protest leaders were later elected to run the village, would be studied and shared around the rest of the province.

And when Wang Yang was asked about the Chongqing case of Wang Lijun, he deferred, saying, “You wasted your chance” at a question, and “You’re asking the wrong person about that topic.” Wang said, “You ought to ask the Chongqing delegation.”

Bo Xilai has been best known for presiding over what has been called the “Chongqing model,” combining a tough stance toward crime, a socio-economic model emphasizing a more equitable distribution of wealth, and a revival of Maoist-era “red” sloganeering, including organized sessions to sing “red” songs and ordering the local television station to show patriotic “red-themed” shows.

The “Chongqing model” has been contrasted to Wang Yang’s “Guangdong model,” which puts less emphasis on economic fairness, and more on sustaining high levels of growth.

Bo on Friday defended his Chongqing model, saying, “"If only a minority of people are wealthy, then we would be heading towards capitalism and we would have failed.” He said the anti-crime campaign and the singing of red songs would continue.

He also pushed back against unnamed critics who he said were spreading “filth” against him and his family, including widespread Internet rumors that his son, Bo Guagua, drives a Ferrari sports car. “Some people have made false charges against me, and even my family,” Bo said. “I am very angry about this.”

He said Bo Guagua was able to attend Oxford University and Harvard because of scholarships.

Researcher Zhang Jie contributed to this report.