Jeremy Crook, 53, former European vice-president of software firm Peregrine Systems, had preferred to fly to the United States on his own accord to face the allegations, which he denies.

He even went so far as to book a flight for next Tuesday and was understood to be in negotiations with the US Department of Justice about potential bail conditions.

But when he went to City of Westminster magistrates court on Wednesday to request his passport back, he was refused -- and told he must face full extradition proceedings.

If he does not appeal the ruling, or if he loses an appeal, he will be arrested and accompanied by US marshalls onto a flight to the United States in a scene repeating the extradition of three NatWest bankers implicated in an Enron-related fraud case in Texas.

In contrast to Crook, the NatWest Three challenged their extradition in the courts with support from London's business and financial elite who unsuccessfully appealed to Prime Minister Tony Blair to intervene.

Crook's lawyer, Steve Law, said the US Justice Department was happy for his client to travel on his own accord, and that it was the British authorities who intervened.

"We have no beef with the States. They have been perfectly civil," Law said.

"It is only because of the United Kingdom authorities getting involved that the matter has become uncivil.

"They are doing all they can to stop Mr Crook surrendering because they fear that he will return to the United Kingdom and make a noise about the extradition treaty."

Law said his client has until September 4 to appeal to the High Court. Otherwise he will have to cross the Atlantic "under arrest with marshals".

Peregrine Systems, based in San Diego, southern California, collapsed in 2002 after a major accounting scandal that saw a number of senior managers accused of fraud.

Crook's name was added to the indictment in 2004, after which his passport was taken from him. If convicted, he could be jailed for up to 86 years.

A Home Office spokeswoman said Crook had two chances to surrender voluntarily -- one before magistrates court assessed the extradition request, and the other before the extradition warrant was signed off earlier this month.

"As this matter may come before the courts again, it is not appropriate to comment further," she added.

The NatWest Three -- David Bermingham and Giles Darby and Gary Mulgrew -- are to go on trial in Houston, Texas on September 11 for their alleged 19 million dollar (15 million euro) fraud.

US prosecutors claim the trio lined their pockets by conspiring with Enron executives to get their employer -- now a part of Royal Bank of Scotland -- to sell off a stake in an offshore company for much less than it was worth.

They tried but failed to resist extradition, on grounds that the alleged fraud took place on British soil against a British bank that never claimed to have been the victim of fraud.

The British government found itself under intense political pressure over the case, because a US-British treaty under which they were extradited has not been ratified by the US Congress.

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