A high-profile politician in southwest China is reported to have suddenly gone on leave, amid rampant speculation about a possible political scandal involving a rising star in the Communist leadership.

The Chongqing city government said Wednesday that Wang Lijun was undergoing “vacation-style treatment” because of “long-term overwork, a high level of mental stress and physical exhaustion.”

Since being dismissed last week as Chongqing's police chief, online postings have suggested Wang had a falling-out with the city's powerful Communist Party secretary, Bo Xilai. Some have even suggested that he sought asylum at the U.S. consulate in Chengdu.

The situation is a potential embarrassment for Bo, who was widely expected to be appointed to a top position in the Communist Party leadership transition later this year.

Wang, who also served as deputy mayor of Chongqing, gained national prominence after being appointed by Bo to lead a crackdown against organized crime, which resulted in the arrest of scores of senior officials in the city-province.

The Chongqing government's announcement of Weng's sick leave came hours after witnesses reported large numbers of police around the U.S. consulate in Chengdu, blocking off roads around the building.

A spokesperson for the U.S. Embassy in Beijing said he could not comment on any reports of an asylum bid or an increased police presence. China's foreign ministry declined to comment on the increased security around the consulate.