Swiss prosecutors have launched criminal proceedings after the law firm at the centre of the international Panama Papers tax scandal alleged that a computer at its Geneva offices was hacked, Swiss media reported yesterday.

A Geneva-based computer expert working for Panama law firm Mossack Fonseca was detained for alleged data theft several days ago in Geneva, Swiss newspaper Le Temps reported, citing an unnamed “source close to the case”.

“What we know is that the data were downloaded from his computer in Geneva and that he had all access rights,” Mossack Fonseca’s lawyer Thierry Ulmann told Le Temps, adding that this formed the basis of the criminal complaint that it filed with Swiss authorities.

Mossack Fonseca’s Geneva office did not immediately reply to queries from dpa.

The unnamed suspect denies all accusations against him, his lawyers Thomas Barth and Roman Jordan were quoted as saying by the regional newspaper.

A spokesperson of the Geneva judicial authorities confirmed only that prosecutors had initiated criminal proceedings in reaction to a criminal complaint filed by Mossack Fonseca, which is headquartered in Panama.

The spokesperson did not provide any details on the charges that have been filed or the stage of the proceedings, Swiss news agency sda reported.

The massive data leak by Mossack Fonesca in April put numerous politicians, athletes and celebrities in the spotlight by detailing how money was secretly funneled to shell companies in tax havens.

An unnamed source calling himself John Doe handed over 2.6 terabytes of confidential data to the German newspaper Sueddeutsche Zeitung, which then analysed the information together with a number of international media outlets.

- dpa