The bank was operating normally, the statement added.

The party's graft-fighting body, the Central Commission for Discipline Inspection, said on Friday it was probing Lu, who it identified only as the former chairman of Beijing Energy Investment, although it gave no details.

Beijing Energy Investment holds 5.08 percent of the bank's shares. Bank of Beijing has a market value of 106 billion yuan ($16.93 billion) and operates primarily in the domestic market.

The Chinese government's probe into the financial sector comes as part of a broader campaign to root out corruption at major state-run conglomerates.

The official Xinhua news agency said on Monday that anti-graft teams would be sent into 72 major state-run firms, including 19 in the financial and rail sectors.