Online gaming firm Betonsports has shut down its website following the arrest of its chief executive in the US on charges of racketeering.
Online gambling firms are playing for high stakes
David Carruthers was named in an indictment in Missouri after an investigation into internet gambling.
Trading in shares of the firm, which is listed in the UK, has been suspended.
Mr Carruther's Texas-based lawyer, Tim Evans told BBC Radio 4's Today programme that he was "hopeful" of securing bail for his client on Friday.
"The government has asked the judge to detain him until such a time as a trial can be had, which will be months away, so we are very interested in getting a court order that allows him to be released, " Mr Evans said.
Visitors to the Betonsports website are told: "In light of court papers filed in the United States, the company has temporarily suspended [its website] pending its ability to assess its full position.
"During this period, no financial or wagering transactions can be executed."
Mr Carruthers, 48, is named on a 22-count indictment, issued by a federal grand jury after US investigators used assumed identities to gamble on the site.
The indictment charges 11 individuals and four businesses, including Costa-Rica based Betonsports - which is accused of illegally taking bets from US residents and failing to pay US taxes on wagers.
The chief executive was travelling to Costa Rica when federal authorities arrested him at Dallas airport as he changed planes.
He and his wife, who have lived in Costa Rica since 2000, were returning from the company's annual meeting in London.
A warrant has been issued for the arrest of Betonsports founder Gary Stephen Kaplan, 47, who is charged with 20 offences including tax evasion and conspiracy.
Betonsports, whose holding company Betonsports plc is listed on London's Alternative Investment Market, is based outside the US because of strict gaming laws there.
Mr Carruthers has been an outspoken opponent of a proposed US law banning banks and credit card companies from processing internet gambling payments.
Betonsport is just one of the companies cashing in on an internet betting boom and has 1.2 million customers worldwide, many of them in the US, where online gaming is a $12bn-a-year business that is expanding.
This is despite the government's opinion that it violates a law against placing interstate bets using telephone lines.
The action in the US hit the online gaming sector, wiping hundreds of millions of pounds off the value of companies listed in the UK.