Bo Xilai, the charismatic Communist Party leader of the Chinese city of Chongqing, has been removed from his post in the wake of a scandal involving a former aide.

China's official Xinhua news agency released a brief statement Thursday saying Bo is being replaced by Vice Premier Zhang Dejiang. The statement gave no reason for Bo's dismissal.

The 62-year-old Bo had been considered a contender for a leadership post in the party's all-powerful Politburo Standing Committee. But his standing has been in doubt since Wang Lijun, his longtime police chief, went to the U.S. Consulate in Chengdu last month in what was reported as a bid to seek asylum.

Xinhua said Wang has been placed under investigation and was removed Thursday from his post as deputy mayor of Chongqing.

Speculation about Bo's future intensified when he failed to appear for a meeting of the Politburo last week. He appeared the next day during a meeting of the National People's Congress and told reporters he had made a mistake by trusting Wang.

“After this problem came out, I was very sympathetic. I feel like I put my trust in the wrong person. So this incident is something we need to investigate thoroughly until we get to the bottom of it.”

He also said the incident should be thoroughly investigated.

Premier Wen Jiabao issued a public rebuke of Bo on Wednesday, telling reporters that party leaders in Chongqing “must seriously reflect” on the Wang Lijun incident and “learn lessons” from it.

Bo, a son of one of the founders of the communist China, gained prominence when he and Wang launched a crackdown on corruption in the city of 30 million people, resulting in the arrests and convictions of scores of officials. He also began a so-called revival of “red” cultural themes and slogans from the era of Chairman Mao Zedong.

Beijing-based analyst David Kelly has told VOA that critics of the campaign saw it as a move in the wrong direction.

“The methods used by Mr. Wang Lijun with the approval of Mr Bo Xilai were in a sense going backward rather than forward on the scale of rule of law. People were being rounded up and there wasn't a lot of attention given to their legal defense or their, the evidence base, and this was certainly the criticism made by some prominent jurists in China.”

Bo Xilai continues to be listed as a member of the party's 25-member Politburo. If he loses that seat, it will be the first time a sitting member of the Politburo has been removed since 2007, when Shanghai Communist Party chief Chen Liangyu was replaced.