The Hungarian news agency MTI reported the facts in the case, the Budapest business daily BBJ said the price of MOL stock dropped by more than 100 forints since the news was published to 15,930 forints.
The Portfolio.hu portal said Hungarian analysts and economic experts believed that Hernadi would keep his position and MOL the management rights in INA, but that the story could negatively impact the stock price.
Reuters quoted MOL's general counsel Pal Kara as saying that the citing of flight risk for Hernadi was "unreasonable and baseless".
An investigating judge issued a detention order citing flight risk and now an arrest warrant can also be issued.
Serbia's news agency Tanjug said it was highly unlikely that, given the stance of the Hungarian state prosecution so far, they would act on the arrest warrant and that they could refer to the fact that Hungary investigated the case and found nothing contentious.
Kara told Reuters that "due to lack of any criminal act," the Hungarian prosecutors "closed the case."
Croatian prosecutors decided on the detention order after Hungarian authorities recently refused to serve Hernadi with a summons to be questioned in Croatia and prior to that would not question him themselves, citing the protection of national interests.
Kara said he had no knowledge of any request from Croatia to question Hernadi, while Tanjug said the question was "whether they ever delivered the summons to Hernadi."
Slovenian and Austrian media too reported about the case.
MOL holds a 49.1 per cent stake in INA, while the Croatian government holds 44.84%.