Weekly magazine Der Spiegel reported on Sunday that the 75-year-old's house in Ammersee was visited by detectives from Bavaria as well as colleagues from Rhineland North-Westphalia, where authorities had bought the data about UBS customers.
Baselitz, whose paintings regularly fetch millions of dollars at auction, moved out of a castle in Lower Saxony seven years ago, to live in a specially commissioned glass and wood house on the edge of Lake Ammer in Bavaria, the magazine said.
UBS says it has been actively urging its customers with tax issues to sort them out. Baselitz' secretary said he had not avoided millions of euros of taxes, and that there was no arrest warrant when his house was searched. But there was no denial of the tax investigation, nor that there had been an outstanding tax bill which he had paid.
Der Spiegel reported that he had possibly heard of the raid in advance - and that as the officials knocked on his door, he was en route to another home he has in Italy.