Germany's largest bank broke off its relationship as a correspondent bank for US dollars with Danske in Estonia in September 2015 due to concerns over non-resident customers — who came predominantly from Russia and other ex-Soviet states — at the branch, according to people familiar with the matter and a report by the Danish regulator.

A senior Deutsche employee made the comments as the relationship was terminated, also warning Danske against Moldovan customers and clients transferring money to Moldova.

Danish financial regulators stated in a report in May — which mentioned the events but did not identify the bank as Deutsche — that it had not received any "material showing that Danske Bank investigated those of its customers that had relations to Moldova on the basis of this."

A representative of Deutsche said at a meeting between Deutsche and Danske that out of ten non-resident customers from the Estonian branch, the correspondent bank would be comfortable only with servicing one given the customers' characteristics.

Deutsche itself paid $630 million to settle US and UK investigations into alleged mirror trades used to launder $10 billion out of Russia between 2011 and 2015.

JPMorgan was the first correspondent bank for US dollars to terminate its relationship with Danske in Estonia in 2013, with the Danish regulator report — once again not identifying the bank by name — saying it was due to concerns about non-resident customers.

Danske is gearing up to release its own conclusions from year-long internal investigations into the money laundering scandal on Wednesday.