SHANGHAI (REUTERS) - China is investigating the former head of state-owned Bright Dairy & Food on suspicion of serious disciplinary violations, the country's anti-graft watchdog said on Wednesday, employing its usual euphemism for corruption.

The regulator has opened a probe into Guo Benheng, who departed the firm last month, the Shanghai branch of China's Central Commission for Discipline Inspection (CCDI) said in a statement. It did not supply additional details about the case.

China's top graft-busting agency lambasted the country's powerful state-owned industries earlier this month as being riddled with corruption.

President Xi Jinping has warned that official graft is serious enough to threaten the Communist Party's legitimacy and has vowed to go after powerful "tigers" as well as lowly"flies".

Guo left Bright Dairy in June for "personal reasons", Bright spokesman Pan Jianjun told Reuters. He added the probe would not have any impact on the company's business and that he did not know any further details about the investigation.

Bright Dairy's state-owned parent Bright Food Group Co Ltd has been one of the most active Chinese firms on the global market, snapping up deals for global firms from Israeli foodmaker Tnuva to British cereal brand Weetabix.

Beijing is expected to unveil a master plan to reform the powerful state-owned sector, but one has yet to be published.

Senior executives at automaker China FAW Group Corp, Baosteel Group and China National Petroleum Corp have all been put under investigation for corruption this year.