BEIJING, April 4 -- Ma Xingrui, a member of China's elite Politburo who had risen rapidly through the ranks after working as a rocket scientist, is under investigation over suspected "serious violation of law and discipline".

China is stepping up its years-long fight to root out corruption with the purge of sitting members of the Politburo, the ruling Communist Party's decision-making body, with Ma the third member targeted in the past six months.

Ma, who also serves as the deputy leader of the central rural work leading group, is undergoing a disciplinary review and supervisory investigation, the Central Commission for Discipline Inspection said in a notice yesterday.

The anti-graft watchdog did not disclose any details regarding the ...