Updated

The Nordic region's largest bank says it will close 68 accounts at its Luxembourg branch as it adopts tougher rules on clients using offshore companies.

Nordea Bank found that although its employees provided administrative services to customers it found no evidence they had initiated the "establishment of offshore structures" or had contributed to customers' tax evasion.

Nordea CEO Casper von Koskull said Wednesday that the bank does not accept being used as a platform for tax evasion or aggressive tax planning.

The internal investigation came after Swedish broadcaster SVT, one of hundreds of media with access to leaked documents detailing offshore accounts, reported that Nordea's Luxembourg unit worked with Panamanian firm Mossack Fonseca to help customers set up shell companies.