If it was a Robert Ludlum thriller it would be called The Liechtenstein Affair or The Zumwinkel Doctrine. Without a cold war to prosecute, Germany's spies have turned on suspected tax evaders, paying at least €4m to a former employee of Liechtenstein's biggest bank for a list of Germans with money in trust in the principality. There must be tight controls on the ability of governments to spy on their own citizens, but unco-operative tax havens deserve this kind of treatment.

The spies' information led to a raid on the house of Klaus Zumwinkel, who resigned last week as chief ex-ecutive of Deutsche Post, amid allegations he failed to pay €1m of tax due on a Liechtenstein trust. Liechtenstein's laws on bank secrecy make those of neighbouring Switzerland look positively indiscreet. Since 2000, 35 unco-operative jurisdictions have been removed from an Organisation for Economic Co-operation and Development blacklist, including Jersey, Bermuda and the Cayman Islands. Liechtenstein is one of only three that remain.