Advisor Accidentally Mails List of Tax Cheats, Authorities Zone In

Bloomberg says U.S. authorities appear to be picking off the clients on that list one by one. Among those affected: Jacques Wajsfelner, an 83-year-old exile from Nazi Germany, and Michael Canale, a retired U.S. Army surgeon. Another customer, cancer researcher Michael Reiss, pleaded guilty, though his court records don't mention the list.

"He was sending mail to someone in the United States, and apparently in error he included a list of U.S. taxpayers," Assistant U.S. Attorney Dan Levy said on March 5 at Wajsfelner's sentencing in New York. "The government has mined that list to great effect and prosecuted a number of people who were on that list."

Wajsfelner, who pleaded guilty to hiding $5.7 million from the Internal Revenue Service, was sentenced to three months of house arrest.

The case comes as negotiations continue between Swiss banks and U.S. authorities over the latter's access to once secretive accounts. Long a haven for ultrawealthy individuals and families,  the United States has increased pressure in recent years to open accounts of suspected tax cheats.