STOCKHOLM/HELSINKI (Reuters) - Swedish banking group Nordea said it would end its end its association with law firm Mossack Fonseca at the centre of the Panama Papers scandal.

“We will not cooperate with Mossack Fonseca any longer. Absolutely not”, Nordea CEO Casper von Koskull told public service broadcaster SVT on late on Monday. “The bank should not be used as a platform for tax evasion.”

Sweden’s Financial Supervisory Authority has contacted authorities in Luxembourg for information related to allegations that Nordea, the Nordic region’s biggest bank, helped some clients set up accounts in offshore tax havens.

The allegations against Nordea appeared in a leak of more than 11.5 million documents from the files of law firm Mossack Fonseca, based in Panama.

While setting up offshore accounts is not necessarily illegal it could be in breach of Swedish money laundering rules.

Nordea has said it would review all activities relating to offshore accounts in Luxembourg. The bank said it strongly denounced tax evasion and had taken proactive measures since 2009 to ensure all customers’ holdings and income on their accounts were reported to the tax authorities.

According to SVT, one of the media outlets to cooperate on the publication of the Panama Papers, Nordea has helped to set up between 300 to 400 letter box entities--firms without any real existence other than letter boxes in a tax haven--and is mentioned more than 10,000 times in the Panama Papers.

The allegations about Nordea’s activities has prompted criticism from politicians. “Nordea has lost all its credibility to operate in the interest of mortgage takers,” Finland’s foreign minister and the head of the nationalist Finns party, Timo Soini, said in a blog post on Tuesday.

Sweden’s Prime Minister Stefan Lofven said on Swedish television on Monday: “I think it is shameful that they have been involved in this. They say they have pulled out of this. I hope that’s true.”

Nordea was not immediately available for comment on Tuesday.

(Reporting by Johan Ahlander and Jussi Rosendahl. Editing by Jane Merriman)