David Carruthers, chief executive of online betting site Betonsports.com, has been detained by Federal agents while changing planes in the US.

It is not clear whether he has been detained because his website accepts bets from US gamblers or if he fell foul of other US border rules - which are many and various. Since last year it has been illegal to carry a cigarette lighter onto an aeroplane bound for the US.

Carruthers was on his way to the company's offices in Costa Rica, Reuters reports.

While US authorities regard online gambling as illegal, the situation is unclear and a gambling bill is currently being considered by Congress.

News of the bill sent shares in other gambling websites tumbling. The markets have been wary of online gambling because of worries about US regulators.

Sportingbet shares fell 10 per cent and Partygaming shares were down nearly five per cent. Betonsports shares had plummeted nearly 20 per cent at the time of writing.

A spokeswoman for Betonsports told The Reg: "There is not much more we can tell you. He was detained, not arrested, while travelling through the US on his way to Costa Rica. He was stopped at Dallas airport."

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