British day trader Navinder Singh Sarao, who is accused of helping to trigger a multibillion-dollar Wall Street crash from a suburban London home, has lost a High Court challenge against a decision that he can be extradited to the US to stand trial.

Sarao, 37, dubbed the Hound of Hounslow, is wanted in the US over allegations that he contributed to the 2010 Wall Street 'Flash Crash' from his parents' home 3,500 miles away in west London.

US authorities claim the Briton made $875,000 (about £716,000) on May 6 2010, the day of the crash, part of alleged illegal earnings of more than $40m (£26m) 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.

At an earlier extradition hearing at Westminster magistrates court in March also ruled that Sarao could be sent to stand trial in the US.

Lawyers for the former bank worker and Brunel University student had argued that his actions did not constitute a crime.