Declining to reveal the identity of suspects, the Interior Ministry said in a brief statement that three suspects were under investigation on suspicion of wrongdoings related to the sale of electricity at a very low price which caused damage to HEP.

The national anti-corruption investigative agency (USKOK) ordered the probe.

Mravak's lawyers, Ante Madunic and Tomislav Grahovac, told the media that they had not yet been acquainted with the details or charges which their client might face.

According to the media, Mravak is suspected of harmful contracts and losses caused in 2007 and 2008, when HEP bought electricity at international tenders at the highest prices, only to sell it at considerably lower prices to the Sibenik-based TLM metal company, which gave it to the Aluminij company from Mostar, Bosnia-Herzegovina. In this way, HRK 100 million was embezzled from the state budget.

Since last September, Mravak and four other HEP executives have been under suspicion of abuse of office and defrauding HEP of nearly HRK 700,000 by enabling Rade Buljubasic, a returnee from Australia, to receive an HEP employee salary for four years, although he was not working at HEP but at the Zagreb headquarters of the HDZ, the ruling Croatian Democratic Union party.

Mravak was dismissed from HEP at the government's proposal.