COPENHAGEN, Denmark — The United States government has opened a criminal investigation into the flow of dirty money through the Estonian branch of Denmark's biggest bank, the lender said Thursday.

Danske Bank says it is "in dialogue" with the U.S. Department of Justice, which had asked for information after an internal report at the bank detailed a massive amount of money laundering through its subsidiary, with some reportedly even linked to family members of Russian President Vladimir Putin.

Danske's interim chief executive, Jesper Nielsen, said "it is too early to speculate on any outcome of the investigations."

The results of Danske Bank's internal investigation were published last month and found that some 200 billion euros ($235 billion) flowing through the bank's accounts from 2007 to 2015 was suspicious. Its CEO resigned over the case.

The findings prompted Denmark's financial regulator to reopen a probe and Danish prosecutors have started a criminal investigation.

Danske Bank building
General view of the Danske Bank building in Copenhagen, Denmark, September 27, 2018. Jacob Gronholt-Pedersen

The bank also said that Danish regulators have ordered it to reassess its finances to make sure it has enough capital to cover any potential fines or other losses related to the scandal.

The bank said Denmark's Financial Supervisory Authority told them its solvency need should amount to at least 10 billion kroner ($1.55 billion).

As a precaution, Danske Bank decided to discontinue a share buy-back programme. The share buy-back for a total of 10 billion kroner, with a maximum of 85 million shares, was due to end by Feb.1.