The state prosecutor of Connecticut is investigating whether any state residents were among the 4,450 named recently as US customers by UBS, according to Reuters.

"UBS is naming names of tax evaders, and we have reason to believe Connecticut citizens are among them," the attorney general said. "We will vigorously pursue them for unpaid taxes, including anyone who comes forward under the federal tax amnesty programme."

The comments came after UBS earlier this month agreed to hand over details on the accounts of 4,450 US clients to the Internal Revenue Service, in a deal brokered by the Swiss and US governments. The move has led observers of the wealth management industry to conclude that traditional Swiss bank secrecy has been eroded and that the IRS will seek to hunt down tax evaders at additional Swiss, and possibly other, banks in offshore centres.