Werner Mauss, 77, a former private investigator who has since become infamous for his work with police and intelligence services, was also ordered to donate £178,000 to charity.

His supposed record – much of which is nearly impossible to confirm – includes negotiating for the release of prisoners, foiling assassinations and capturing international terrorists.

Judge Markus van den Hövel took Mr Mauss’ record of public service into account when suspending the sentence.

He said: “His is a great achievement, for which the court has the highest respect.”

Mr Mauss was initially accused of evading nearly £12 million in taxes on profits from offshore investments over a ten-year period, which he claimed did not belong to him but to Western intelligence agencies financing his work.

The judge declined to rule on whether that was true, instead finding that the money had passed into Mr Mauss’ possession at some point and therefore should have been declared in his tax return.

The court agreed that he had evaded a maximum of around £2 million.