British financial trader accused of helping to trigger a stock market crash which wiped billions of dollars off the value of US shares has told a court he will fight a request for his extradition to America.

Navinder Singh Sarao was arrested at the request of US authorities over the 2010 Wall Street "flash crash", which he allegedly helped cause from his home 3,500 miles away in Hounslow, west London.

The 36-year-old is charged with wire fraud, commodities fraud and market manipulation, the US Department of Justice said.

He is also facing civil claims from US regulators who allege he and his company, Nav Sarao Futures Limited, illegally made 40 million dollars (£27 million) over five years.

Asked whether he consented to his extradition to the US at Westminster Magistrates' Court today, Sarao replied: "No."

Sarao appeared in the dock wearing a yellow sweatshirt and white tracksuit trousers. He faces 22 charges in the US state of Illinois, prosecutor Aaron Watkins told the court.

They include ten counts of commodities fraud, each of which carried a sentence of 25 years, a single count of wire fraud, which carries a sentence of 20 years, ten counts of commodities manipulation and attempted commodities manipulation, and one count of "spoofing", both of which carry a maximum sentence of ten years.

Joel Smith, defending Sarao, said: "This is a matter that has come as something of a bolt from the blue for Mr Sarao."