The leader of the southwestern Chinese city of Chongqing says he is not sure when his predecessor, disgraced senior politician Bo Xilai, will stand trial.

Vice Premier Zhang Dejiang was put in charge of the megacity after Bo was ousted because of a murder and corruption scandal involving his wife, Gu Kailai.

Speaking on the sidelines of a pivotal Communist Party meeting in Beijing, Zhang told reporters he has seen no evidence that the British businessman murdered by Bo's wife was a spy for the British government.

The Wall Street Journal reported this week that the businessman, Neil Heywood, was an informant for the British spy agency MI6.

The scandal has upset the party's once-a-decade power transfer that begins with the 18th Party Congress this week. The charismatic Bo was once considered a favorite for a top spot in China's inner core of leaders.

The 63-year-old ex-Politburo member, who is expected to soon stand trial for charges including corruption and covering up his wife's murder, enjoyed widespread popularity among Chinese leftists because of his calls for a Mao-era “red revival.”

His policy of supporting state-owned enterprises and top-down governance became known as the “Chongqing model,” and is considered responsible for transforming the city into a thriving metropolis.

But Zhang on Thursday sought to bury Bo's legacy, telling reporters that he believes the “Chongqing model does not exist at all.”