The long-awaited final report by two court-appointed inspectors into the affairs of National Irish Bank has found widespread corrupt practices and encouragement of tax evasion at the bank.

The six-year investigation, set up by the High Court, appointed inspectors Tom Grace and John Blayney following an application in 1998 by the Minister for Enterprise, Trade and Employment, Mary Harney.

The Inspectors found that NIB personnel targeted monies which were not disclosed to the Revenue for investment in CMI policies. CMI was an offshore investment scheme used by some of its clients.

The report said bank personnel promoted CMI policies as a secure investment for funds which had not been declared to the Revenue, thereby facilitating tax evasion by third parties. Potential investors were also assured that their investment would be kept confidential from the Revenue.

The Inspectors found that the bank improperly charged sums of money as interest to some customers. They said this money, when discovered by the bank's internal audit, should have been immediately refunded. The Inspectors said they did not accept that NIB had identified all incidences of improper interest charges, though it has refunded IR£570,000 on 564 accounts in 12 branches.

The report found that bogus non-resident accounts were opened and maintained by NIB and were 'widespread' in the branch network in the period covered by the report.

They said this constituted an 'unlawful and improper practice' which encouraged tax evasion on the funds deposited and the interest.

The inspectors found that the way branch managers purported to charge fees for administration was improper, resulting in some customers being overcharged across the branch networks. It also found that some customers at branches other than Carndonagh, Cork and Waterford have not been refunded.