CHANGCHUN, Aug. 29 -- A former senior executive of China's leading carmaker FAW Group Corporation is under graft probe, just three days after two senior executives of a joint venture of the company were investigated.

An Dewu, former deputy general manager of FAW, was investigated for suspected serious violations of discipline and law, said the discipline watchdog of the Communist Party of China in Jilin Province, where the company is based.

Li Wu, former deputy general manager of FAW-Volkswagen Automobile Co. Ltd. and Zhou Chun, deputy general manager of the carmaker's Audi sales department, were investigated for suspected "serious violations of laws," authorities announced Tuesday.

FAW Volkswagen ranked the first place among Chinese auto makers by selling 810,200 sedans in the first six months of 2014, according to the China Association of Automobile Manufacturers.

FAW, one of China's largest state-owned carmakers, sold 1.53 million vehicles in the first half of this year, up 9.9 percent year on year.