Authorities in North Rhine-Westphalia are to buy a CD with data concerning around 1,000 German clients of the private Couts Bank, a subsidiary of the Royal Bank of Scotland.
It will be the first time German authorities will buy data on suspected tax cheats since Berlin and Bern signed a deal on double taxation in August that will come into force in 2013 and could net billions of euros for German tax coffers.
The accord aims to close a dispute between the two neighbours that blew up into a major spat in 2010 when German authorities raided branches of Credit Suisse bank in 13 German cities after buying data on suspected tax dodgers.
Switzerland reacted angrily, saying the data -- bought for a reported €2.5 million -- was stolen in violation of its banking secrecy laws.
According to German media, between €130 and €180 billion in German assets are hidden in Switzerland.