The Zagreb-headquartered company only confirmed that USKOK investigators had visited INA to hand the summons.

In May 2011, the then president of the the Croatian Financial Services Supervisory Agency (HANFA), Ante Samodol, pressed charges against MOL and responsible executives in the company on suspicion that they committed a fraud in business operations through manipulation with INA shares on the financial market.

In early 2011 HANFA suspended trading in INA shares on the Zagreb Stock Exchange several times explaining that while monitoring trading in INA shares, it had found significant trading by foreign investors, so it had asked relevant foreign regulators for necessary information in order to ensure transparent trading, protect investors and ensure regular and orderly trading on the capital market.

"As certain information on investors was gathered in the meantime, HANFA believes that in order to protect investors and secure regular trading in an organised market, it is necessary to prolong the suspension until the end of the trading day on April 8," HANFA said then in a press release.

HANFA said it had submitted all available information on the investors and the course of trading in INA shares to other authorities in Croatia.

Trading in INA shares on the ZSE had intensified after the Hungarian oil company MOL in December 2010 published an offer to purchase INA shares from small shareholders for 2,800 kuna per share, after which pension funds started buying INA shares for 2,830 kuna. Then unidentified investors also became involved, collecting shares into custodian accounts. Some media speculated that MOL was behind the unidentified buyers in order to exceed its interest in INA above 50%.

At the time the single largest shareholder in INA was MOL with 47.26 per cent of the shares, while the Croatian government held 44.84 per cent.

Upon accusations, MOL rejected media reports about its alleged involvement in manipulation with INA shares.