Nordea Bank AB (publ) and Swedbank AB (publ) said they are not under investigation for possible money laundering in the Baltics amid a decline in their share price following reports that dirty money transactions in the region could be larger than previously expected.

A Nordea spokeswoman told Reuters that the bank has good relations and is in constant communication with authorities, a statement echoed by Swedbank. Birgitte Bonnesen, Swedbank's CEO, said the lender's nonresident customers make up only 1.5% of its total Baltic clients.

Shares in Nordic banks with significant Baltic operations fell Oct. 4 shortly after the Estonian central bank revealed that the country's lenders handled up to €900 billion in cross-border flows from 2008 to 2015.

The regulator clarified that the figure is an aggregate of cross-border payments received and paid from Estonia, including import and export by local companies and routine financial transactions.