Robert Jezic, owner of the Dioki group and the Novi List daily, was arrested around 6 pm in Zagreb on Thursday, according to unofficial reports.
Interior Ministry spokesman Krunoslav Borovec said he could not comment as this was a case within the jurisdiction of the Office for the Suppression of Corruption and Organised Crime (USKOK), which was not available for comment.
Jezic is allegedly the fourth suspect in unlawful transactions between the state-owned power company HEP and Dioki. The other suspects in the case, unofficially, are former Prime Minister Ivo Sanader, who left the country today, Ivan Mrljak of HEP and former HEP board chairman Ivan Mravak.