MANILA, Feb. 16 (Xinhua) -- The Asian Development Bank (ADB) sanctioned 41 firms and 38 individuals for corruption last year, according to a report released on Monday by the Manila-based lender.

    This makes a total of 552 firms and individuals banned from working for the ADB since it began investigating corruption allegations in 1998, the bank said.

    ADB's Office of the Auditor General, Integrity Division, as the focal point of the bank's anti-corruption drive, received 186 complaints in 2008, which resulted in 89 investigations, said the bank.

    It investigated matters ranging from a medical-benefit fraud case by a former staff member involving less than 100 U.S. dollars to alleged collusion in bidding for a road construction project worth more than 10 million dollars.

    According to the report, 74 percent of the cases investigated involved ADB-financed activities, while 18 percent involved ADB staff members. The remainder involved sanction violations and conflicts of interest.

    The firms that were sanctioned are prohibited from doing business with the ADB for up to seven years, while sanctions against individuals range from one year to an indefinite period.

    The bank does not publish the list of firms and individuals that have been investigated or sanctioned from doing business with the institution, but it shares the list with the ADB staff, other international organizations, and others with a need to know.

    The process through which the ADB imposes sanctions is administrative, not a legal or juridical assessment of fraudulent or corrupt practices.

    "The ADB continues to enforce its anti-corruption policy vigorously," Philip Daltrop, Auditor General of the bank, said in a press release.

    "We investigate all allegations as quickly as possible and sanction both firms and individuals where this is justified by the findings of the investigations. As part of our investigations, we always seek explanations from those accused of wrongdoing," he added.