A British financial trader accused of helping trigger a multibillion-dollar Wall Street crash from a suburban UK home has lost a High Court challenge against a decision that he can be extradited to the US to stand trial.
Navinder Singh Sarao, 37, dubbed the Hound of Hounslow, is wanted in America over allegations that he contributed to the 2010 Wall Street ''Flash Crash'' from his parents' home 3,500 miles (5,633km) away in west London.
US authorities claim the Briton made 875,000 US dollars (about £716,000) on May 6 2010, the day of the crash, part of alleged illegal earnings of more than 40 million dollars (£26 million) over a five-year period.
He faces 22 charges, which carry sentences totalling a maximum of 380 years.
At an extradition hearing at Westminster Magistrates' Court in March, District Judge Quentin Purdy ruled that the Londoner, of Clairvale Road, Hounslow, could be sent to stand trial in the US.
Lawyers for the former bank worker and Brunel University student argue that his actions did not constitute a crime.
Two judges at the High Court in London on Friday refused to give him permission to challenge the extradition order.
Sarao, who is on bail, was not present for the ruling by Lord Justice Gross and Mr Justice Nicol.
Lord Justice Gross, announcing the decision to refuse permission, said the court would give its reasons at a later date.
In his ruling in March, Judge Purdy said: ''The causes of the Flash Crash are not a single action and cannot on any view be laid wholly or mostly at Navinder Sarao's door, although he was active on the day. In any event this is only a single trading day in over 400 relied upon by the prosecution.''
He said: "Essentially, has the USA established that the same actions in this jurisdiction at the same time would be capable of being prosecuted for one or more offences known to the criminal law?
"This is not the forum for testing the evidence as in a trial. To my mind, when all is said and done, the USA are correct in arguing they have shown dual criminality.''
The Flash Crash saw the Dow Jones Industrial Average plunge 600 points in five minutes, wiping tens of billions of pounds off the value of US shares.
Lord Justice Gross said during Friday's hearing that "in reality this case is about five years of alleged market manipulation, not about the Flash Crash".
The High Court hearing centred on the legal issue of "dual criminality". Mr Justice Nicol said that what the district judge had to decide was whether the conduct alleged by the US "constituted fraud as a matter of English law".
James Lewis QC, for Sarao, told the two judges: "No-one has ever been prosecuted for this conduct in the UK, ever. You are dealing with something that is completely novel."
The court heard that it now appeared "academic commentary is united in the view that Sarao's activity had little or nothing to do with causing the Flash Crash".
The charges faced by Sarao include wire fraud, commodities fraud and "spoofing" - a practice of bidding or offering with the intent to cancel the bid or offer before execution.
Mark Summers QC, opposing Saroa's application on behalf of the US, said the case was about "spoofing over an extended period".
He told the judges: "The US is ready to proceed to trial."
Leading extradition lawyer Edward Grange, a partner at Corker Binning, said: " Having had his renewed application for leave to appeal refused, Sarao has now exhausted all domestic avenues of appeal."
Extradition "will ordinarily now take place within 28 days from today", he added.
"I t is, of course, open to Sarao to lodge an application to the European Court of Human Rights but his chances of obtaining interim relief preventing his extradition are remote."