The Swiss state owned Banque Cantonale de Geneve has confirmed that hackers have released confidential customer correspondences after the bank refused to pay the ransom demanded by the attackers, reports Tech Week Europe.

The hack, which was revealed on the Twitter account of the hacking person(s) involved involved the theft of over 30,000 emails between the bank and its clients, both domestic and international.

The bank revealed the leak just hours after the ultimatum deadline from the hackers had passed, claiming it preferred "the path of transparency" to blackmail. Bloomberg states that the demand was for "$12,000 at current exchange rates."

Reuters reports that "the hacker played on Swiss banks' reputation for helping clients conceal information from tax authorities", with the following statement tweeted from its Twitter account: "We would like to wish a merry tax audit to all the non-Swiss account holders listed in the BCGE files." The account has since sent out a further 60 messages which ranged from criticizing the bank to taunting their clients it claims are at risk.

Banque Cantonale de Geneve, for its part, denies that there is any need to worry and issued a statement saying it represented "no particular financial risk for clients or the bank."

It continued: "At first analysis, this information is hardly critical, is obsolete or corresponds to foreseen contents about which it has already informed a significant number of clients concerned."

A spokesperson for Banque Cantonale de Geneve added to Reuters that the 30,192 emails intercepted had all been published, and that all the information leaked was client inquiries sent over the internet. None of it involved accounts, which require several passwords or codes to access, she claimed.