Repeated calls to the Chongqing Municipal Commission for Discipline Inspection, which was responsible for investigating Mr. Lei, rang unanswered Friday.

WSJ: Chinese Officials Ousted Over Alleged Sexual Exploits

The Central Commission for Discipline Inspection (CCDI) - the party's top watchdog - announced the decision to expel Liu Zhijun on Monday over "serious disciplinary violations".

BBC: China morning round-up: Railway corruption

Mr. Bo is thought to be in the hands of the Central Commission for Discipline Inspection, a party organization that investigates members' conduct and decides whether they should be dealt with internally or also face criminal charges.

WSJ: With China Trial Over, Focus Turns to Fate of Official