The central bank, the Bank of Slovenia, confirmed that "some of its employees" were being investigated, but declined to comment on local media reports that the bank's governor, Bostjan Jazbec, was among them.

Jazbec sits on the European Central Bank governing council.

The police said the issue was about an assessement of one of the banks rescued by the state in 2013 which meant the bank could scrap its obligations towards holders of subordinated bonds and subordinated debt in the value of 257 million euros.

In 2013 the previous government had to pour more than 3 billion euros into local banks to prevent them from collapsing under a large amount of bad loans. In that way the country also narrowly avoided an international bailout.

As part of the bank overhaul about 600 million euros of subordinated bonds were scrapped in five banks.

In 2014, the Slovenian Association of Small Shareholders filed several court cases against the Bank of Slovenia and local banks, claiming the subordinated bonds and shareholders' capital in rescued banks should not have been erased. None of the cases have been finished yet.

The Bank of Slovenia had repeatedly rejected allegations that it mishandled data used when putting together a rescue package for Slovenia's banks.