Updated

Swiss media report that U.S. prosecutors are poised to step up their probes of wealthy U.S. tax evaders using the tiny principality of Liechtenstein.

Zurich daily newspapers Neue Zuercher Zeitung and Tages-Anzeiger say the U.S. Justice Department has requested statistical data on U.S. clients of Swiss banks with interests in companies or foundations in Liechtenstein.

The reports Wednesday each describe the prosecutors' request for information by the end of this week as a potential new front in the long-running U.S. probe into more than a dozen Swiss banks, including UBS and Credit Suisse and private banks such as Wegelin & Co., which is closing after admitting to helping American tax cheats.

The papers describe the letter as an informal request that could lead to a formal tax probe.