A withholding tax on German money in Swiss bank accounts could be the solution to legalise untaxed money in Swiss private banks, Walter Berchtold, the chief executive of private banking at Credit Suisse, said.

“One could implement a simple withholding tax on assets domiciled in Switzerland. This may be perceived as injustice, but would, on the other hand, help the German state to raise more money, as, in the shortest time possible, all assets in Switzerland could be detected,” Mr Berchtold told Handesblatt, a Düsseldorf-based business daily.

This, he added, would be different to a tax amnesty, as in the case of an amnesty, citizens have to declare their assets, whereas in the case of a withholding tax the money would automatically be taken from the bank accounts.

The bank has about SFr100 billion ($94 billion) in assets from European neighbouring countries; however, Mr Berchtold said that he does not know how much of this is untaxed.

With regards to the disc with stolen account data which has been prominent in the media recently, and which has been acquired by at least one of the German states, he said that he does not know whether it contains data from Credit Suisse, something that had been speculated over the last few weeks.

“By the way, I find it alarming that a constitutional state buys stolen data and thereby creates an incentive for criminals,” he said.