Leumi said it is aware of an investigation being conducted by the German authorities relating to bank customers that allegedly did not report to the German tax authority regarding accounts held with banks outside Germany.

The prosecutor's office and tax fraud investigators were not available for comment on Sunday.

Banking secrecy has been steadily eroded over the past few years after the global financial crisis and rising national debts raised public pressure on governments to make it harder for wealthy individuals to shield their money from tax.

According to the magazine report, the German authorities are basing their probe on a data CD that the State of North Rhine-Westphalia bought in late 2013 from a foreign whistle-blower. Several prominent and wealthy people - one holding 80 million euros $110 million) in assets - are being targeted, the report said.

German prosecutors have made several raids in investigations into tax evasion, some of them following tips found on CDs of data. Swiss officials have accused the Germans of breaking Swiss laws on banking secrecy and of committing economic espionage.

(Reporting by Steven Scheer and Arno Schuetze; Editing by Ruth Pitchford)