China's foreign ministry Thursday confirmed that former Chongqing police chief Wang Lijun had visited the US consulate in Southwest China and stayed there for a day, according to a statement released Thursday via the Xinhua News Agency.

"Chongqing's vice mayor Wang Lijun  entered the US consulate in Chengdu on Monday, and left a day later.  Related departments are still investigating this incident," the statement said, without elaboration.

Wang was elected vice mayor in May last year while continuing to serve as head of Chongqing's public security bureau after successfully leading the campaign to crack down on organized crime.

 On February 2, the Chongqing government announced that he would no longer head the police force, but would only be in charge of the city's education, science and other areas.

On Wednesday, the city government said that Wang was undergoing "vacation-style treatment" because of "long-term overwork, a high level of mental stress and physical exhaustion."

"Wang Lijun did request a meeting at the US Consulate General in Chengdu earlier this week in his capacity as vice mayor. The meeting was scheduled, our folks met with him, ... he later left the consulate of his own volition," Victoria Nuland, a spokeswoman for the US State Department, told the press on Wednesday.

Employees of businesses near the Chengdu consulate told the Global Times Wednesday that there were large numbers of police vehicles in the area on Tuesday night, but said the area was quiet on Wednesday.

The local official newspaper, Chongqing Daily, Thursday published a front page story praising the municipality as "a peaceful and happy home enjoyed by all the people."

However, the story did not mention the name of the city's former top cop Wang Lijun, who was credited as leading the successful three-year crackdown and was hailed by domestic media as a "born hero."