Controversial Russian businessman Denis Ershov has been arrested at the Sarafovo Airport in Bulgaria's Black Sea city of Burgas.

Citing information from sources from the Bulgarian Interior Ministry, private TV station bTV reported Monday evening that the prosecuting authority had not yet been notified about the arrest and the reasons for the step were still unknown.

According to blitz.bg, Ershov was released within an hour after the arrest and he was handed a summons.

According to unconfirmed reports, Ershov will be held accountable for the draining of BGN 1.2 M from fuel company Petrol Holding.

Meanwhile, the website of the 24 Hours daily cited Ershov as saying that he had not been arrested and that he was in his office.

Ershov has been waging a corporate battle the ownership of fuel retailer Petrol AD for nearly two years.

In June 2012, Kalmyk multi-millionaire Kirsan Ilyumzhinov announced that Swiss-based Credit Mediterranee had bought a 52.5% stake in the company, including the stake of Ershov (47.5%) and of Alexander Melnik (5%).

Ilyumzhinov, as cited by dnevnik.bg, claimed that he had negotiated agreements with Mitko Sabev, the owner of the remaining 47.5% stake in Petrol, on a total of 17 court claims filed between Ershov and Sabev.

In 2000, Ershov was banned from entering the country for a period for 10 years as a threat to the national security.

Four years later, the Sofia City Court and the Supreme Administrative Court (VAS) declared the ban null and void.