Russian bookmakers have been forced to publicly deny that their customers’ sensitive information has been hacked and offered for sale to the highest bidder.

The kerfuffle began last week when Dmitry Sergeyev, CEO of bookmaker Digital Betting, posted a note to his Facebook page saying one of the country’s largest bookmakers had been hacked and that the hackers were looking to sell the customer data, including hashed passwords, for 200 Bitcoin (US $146,500).

The hacked data also included answers to security questions. The Bookmaker-Ratings.ru affiliate site claimed this narrowed the field of possible operators to Marathon, Liga Stavok, Zenit, Parimatch and Olimp, with Marathon being the most likely candidate of this group to have a 1m strong database.

Marathon, which generally ranks second on Russian online bookmaker traffic reports, publicly refuted the suggestion that its systems had been hacked, issuing a statement stressing the strength of its online security protocols and assuring customers that they need not be alarmed as to the safety of their personal data.