Swedbank has sacked its chief executive amid a growing money laundering scandal, which the Swedish lender said has heaped “enormous pressure” on its operations.

The lender announced Birgitte Bonnesen’s dismissal shortly before it was due to hold its annual general meeting in Stockholm on Thursday, and comes after reports by Sweden’s state broadcaster threw the lender’s conduct into the spotlight.

Bonnesen is the second Nordic banking boss to be ousted in recent months amid money laundering allegations. Thomas Borgen resigned from Denmark’s largest lender, Danske Bank, last autumn. In September Danske admitted that about €200bn (£178bn) of cash flowing through its Estonian branch was money laundered from countries including Russia, the UK and British Virgin Islands.

Broadcaster SVT’s report alleged that at least 40bn Swedish crowns (£3.2bn) worth of suspicious transactions flowed between the Baltic accounts of Swedbank and Danske Bank between 2007 and 2015.

Swedbank has 900,000 private and 130,000 corporate clients and a market share of about 60% of Estonia’s payments.

“The developments during the past days have created an enormous pressure for the bank,” the Swedbank chairman, Lars Idermark, said on Thursday.

He added: “Therefore, the board has decided to dismiss Birgitte Bonnesen from her position. With that said, Birgitte Bonnesen has during her three years as CEO made an important contribution by creating a leading digital bank with physical presence.”

Swedbank has appointed its chief financial officer, Anders Karlsson, as acting chief executive as it seeks Bonnesen’s permanent replacement.

Bonnesen’s ousting marks a U-turn for Swedbank’s board, which last Friday confirmed its “continued confidence in the CEO and her ability to lead and manage the bank’s work in the fight against money laundering”.

By Monday, it was announcing plans to strengthen its board of directors with a 10th member, meant to boost confidence in the bank “in view of the recent reported on suspected money laundering”. But days later, the bank has ousted its top boss.

The former chief executive initially drafted in external investigators to look into the allegations made by SVT and later confirmed the Swedish financial supervisory authority also had access to the materials.

Last week, the lender announced it was conducting a “deeper review” in cooperation with the relevant authorities and was establishing a financial crime intelligence unit inside the bank “to secure a continued focused approach as criminal behaviour develops over time”.

But it has faced further trouble over its handling of the money laundering allegations in recent days.

The Swedish economic crime authority, locally known as EBM, this week widened its investigation into Swedbank to include fraud. EBM said Swedbank appeared to have spread misleading information to the public and market about what it knew about suspected money laundering across its operations in the Baltics.

EBM’s preliminary investigation did not cover whether money laundering took place but how management handled information of suspected misconduct and presented it to the public and market.