(Reuters) — The Department of Justice and FBI are investigating SEB, Swedbank and Danske Bank over possible breaches of U.S. anti-money laundering regulations, Swedish newspaper Dagens Industri reported Tuesday, sending their shares lower.

Sweden had received requests for help from U.S. authorities investigating a Baltic money laundering scandal that has already led to local fines for Swedbank, Danske and SEB, the newspaper reported.

The banks were being investigated by the DOJ, the FBI and federal police, as well as a federal prosecutor in New York over possible compliance breaches of anti-money laundering regulations and fraud, it added.

"We have previously communicated, for instance in connection with our latest quarterly report, that U.S authorities continue to investigate Swedbank's historic work against money laundering and historic publication of information," a Swedbank spokeswoman said in response to the report Tuesday.

SEB said it had received inquiries from U.S. authorities but was not aware of any allegations against it.

Danske Bank was not immediately available for comment on the Dagens Industri report, which cited unnamed sources.

The FBI and Department of Justice did not immediately respond to requests for comment.

"While all three banks have previously disclosed ongoing AML investigations by 'U.S. authorities,' (the) FBI's involvement and 'fraud' appear to be new," Credit Suisse said in a note.

Shares in all three banks were down, with Swedbank off 7.7%, SEB 5.6% lower and Danske Bank down 3.3%.

While local fines have been hefty, they could be dwarfed compared with any punishment meted out by U.S. authorities.

Deutsche Bank was fined $7.2 billion and Britain's Barclays $2 billion over the sale of toxic mortgage debt in the run-up to the financial crisis of 2008-9.

And this year, U.S. bank Wells Fargo agreed to pay $3 billion to resolve criminal and civil probes into fraudulent sales practices.

Baltic scandal

The scandal first surfaced in 2018 when Danske admitted that suspicious payments totaling €200 billion ($243 billion) from Russia and elsewhere flowed through its branch in Estonia.

It spread to Sweden, where Swedbank was fined a record 4 billion Swedish crowns ($477 million) by the country's Financial Supervisory Authority over flaws in its anti-money laundering work and for withholding information from authorities.

Swedbank lost a third of its market value in 2019.

SEB was fined 1 billion crowns for failures in compliance and governance in relation to anti-money laundering controls in the Baltics.

Swedbank and SEB have both said previously that U.S. authorities were looking at their activities in the Baltic, but not given further details.

Danske Bank said in its 2019 report that it was under investigation by the Department of Justice and the Securities and Exchange Commission.