The seller of the CD containing the data had insisted the handover take place in a neighbouring country because he feared he could be arrested and the CD seized as illegally obtained goods if he entered Germany, the magazine reported.

The handover is apparently being treated as a veritable cloak-and-dagger affair, with the exact location and circumstances known only to handful of investigators.

Germany will pay a reported €2.5 million for the stolen Swiss bank data but could net up to €400 million in unpaid taxes.

The decision by Chancellor Angela Merkel and Finance Minister Wolfgang Schäuble to buy the information has divided German commentators and politicians, given it was stolen.

Some have argued it is simply the price that must be paid to crack down on tax dodgers, while others fear buying stolen information sets a dangerous precedent.

Germany’s foreign intelligence agency the BND was also involved in the meeting, according to Focus.

The seller of the information had first contacted the tax office in the North Rhine-Westphalian city of Wuppertal by email. The initial approach was anonymous but investigators have since established his identity.

Reports of the deal have, according to Focus, sparked a rash of pre-emptive tax declarations, with one account holder revealing his account to Berlin tax authorities and quickly paying back taxes of about €4.5 million.