Federal regulators this week launched an investigation into whether Swiss bank UBS assisted U.S. clients in evading taxes or engaged in securities fraud.

The U.S. Attorney’s Office for the Eastern District of New York, along with the Federal Bureau of Investigation, recently served UBS with a subpoena to determine whether the bank used so-called “bearer securities” to help U.S. clients evade taxes. Such securities are traded from one holder to another without any record of ownership, increasing the risk of tax evasion schemes.

Prosecutors also are looking into whether any of the bank’s executives took part in any criminal activity to cover up the alleged conduct. The investigation was first reported by the Wall Street Journal.  

In 2009, UBS reached a $780 million settlement with the Department of Justice in a separate tax-evasion scheme. As part of that settlement, UBS entered into an 18-month deferred prosecution agreement. Federal regulators also will be looking into whether any potential misconduct took place while under the terms of that agreement.