(UPDATED) The Central Commission for Discipline Inspection is investigating Sun Zhengcai, who until last week was party chief in the major city of Chongqing, for a 'serious discipline violation'

BEIJING, China (UPDATED) – The Chinese Communist Party's anti-graft watchdog has launched an investigation into a Politburo member who was once seen as a contender for a top leadership post, state media reported Monday. The ruling Communist Party's Central Commission for Discipline Inspection officially announced on Monday that 53-year-old Sun Zhengcai, former party secretary of the southwestern metropolis Chongqing, was under investigation for a "serious discipline violation " -- usually a euphemism for a corruption probe. Sun was removed from his position as the party chief in Chongqing on July 15, according to a previous Xinhua report. But by removing Mr. Sun, Mr. Xi has eliminated a potential obstacle to his efforts to consolidate power later this year, when a Communist Party congress will appoint a new leadership team to serve under him for his second five-year stint as party leader and as president. Mr Sun, who was replaced in the city by Mr Xi's former aide Chen Min'er, had once been tipped as a contender for promotion to the Politburo's elite seven-member standing committee, the nation's top political body.
The Chinese Central Commission for Discipline Inspection announces that current Politburo member Sun Zhengcai is under investigation for violating party discipline. Sun is the fourth sitting Politburo member since 1990 to fall from power.