More banks, including two large US lenders, have been contacted about the matter, a report said.

Deutsche Bank and Bank of America have been contacted by US criminal investigators for information about transactions they handled for a small bank branch in Estonia that’s at the center of a major money-laundering case, according to American Banker. Authorities are checking details around one of the biggest money-laundering investigations in history.

The Justice Department investigators have also asked questions about JPMorgan’s work with the branch, another person was quoted as saying. (The story was originally published in Bloomberg.)

This publication has contacted JP Morgan, Deutsche Bank and Bank of America. All three banks declined to comment.

The report said that these banks were correspondent banks for the Tallinn, Estonia, branch of Danske Bank that is the focus of multiple international investigations. The Danish lender acknowledged that the branch moved nearly a quarter trillion dollars’ worth of cash into the global financial system, much of it from potentially illicit activity in Russia. It used the three banks’ global presence to convert foreign cash into US dollars on behalf of its clients from 2007 to as recently as 2015, the report said.

The examination of whether the big banks gave appropriate scrutiny to the Estonia transactions is one aspect of a broader Danske Bank investigation being led by the US Justice Department in Washington and prosecutors from the Manhattan US attorney's office, the report added.

Danske’s AML woes – which have led to the resignation of its chief executive, Thomas Borgen, have prompted calls within the European Union for tougher measures to thwart money laundering.