Members of a Russian gang involved in money-laundering were arrested yesterday in a joint operation between the unit and counterparts in the Russian Federation.
The three men were picked up in a series of raids in St Petersburg and southwest Russia.
The extortion demands occurred alongside denial of service attacks on the betting firms' servers and websites. The attacks bombarded servers with data and shut down the company, which caused financial loss from downtime.
"The success of this operation is built on the foundation of international partnerships between law enforcement and business," said Detective Chief Superintendent Len Hynds, head of the NHTCU. "The more we work together in the fight against organised crime, the safer the UK will be for business."
The gang sent blackmail annual demands by email threatening to continue the attacks unless money was paid.
As part of the investigation, 10 members of the gang were arrested in Riga, Latvia, last November 2003. Officers were able to identify the financial trail which led to the gangsters arrested yesterday. The cash was being moved by a number of money transfer agencies who helped the NHTCU track the money and thereby identified members of the gang.
The investigation was assisted by police from Australia, Canada, Estonia and the USA.