Handcuffed and clad in prison issued clothes, Carruthers appeared in court on Monday along with seven other defendants associated with BetonSports who are accused of breaking US laws which prohibit the taking of bets over the telephone wires. All pleaded not guilty.

Under the terms of a bail agreement negotiated between defense lawyers and prosecutors, Carruthers a 48-year-old Briton, would be required to post a $1 million bond and remain in the vicinity of St Louis, possibly wearing an electronic tag to track his whereabouts. Carruthers has been detained since his arrest at Dallas airport en route from the UK to Costa Rica last month.

In all, 11 people and four companies, including BetonSports, have been named in a 22-count indictment alleging racketeering, fraud, tax evasion and several other offences.

According to US Attorney Catherine L. Hanaway of the Eastern District of Missouri, the indictment was "one step in a series of actions designed to punish and seize the profits of individuals who disregard federal and state laws," suggesting that other online gambling operators may be in the sights of the US authorities.

US Magistrate Judge Mary Ann Medler set a hearing date of August 21 for the defendants who appeared, although this is likely to be postponed.

Separately, US District Judge Carol Jackson extended until August 14 a temporary civil order that prohibits BetonSports from taking bets from the US to allow prosecutors extra time to establish whether the charges were served legally at the company's offices in London and Costa Rica.

BetonSports declined to be represented in the St Louis courts by a lawyer, suggesting that the company is taking the stance that the US authorities have no jurisdiction over its non-US operations.

"By not coming to court, you can make the assumption that since we weren't served, we can carry on our business in a normal capacity," Kevin Smith, a BetonSports spokesman, was quoted by Reuters as stating.

Meanwhile, an arrest warrant has been issued for the company's founder, Gary Kaplan, who is said to currently reside in Costa Rica. He has been charged with 20 felony violations of federal laws ranging from racketeering to tax evasion.