Italian police said Friday they have seized about $6 trillion of fake U.S. Treasury bonds in Switzerland.

The police issued arrest warrants for eight people accused of international fraud and other financial crimes.

The operation, co-ordinated by prosecutors from the southern Italian city of Potenza, was carried out by Italian and Swiss authorities after a year-long investigation.

The fake securities, which amount to more than a third of U.S. national debt, were seized in January from a Swiss trust company where they were held in three large trunks.

The eight alleged suspects have been accused of counterfeiting bonds and credit card forgery.

Deborah Lutterbeck, Reuters.