Arrest warrant issued for JPMorgan supervisor of ‘London Whale’ trader Bruno Iksil

An international arrest warrant has been issued for former JPMorgan executive Javier Martin-Artajo, who oversaw the activities of the London Whale — the trader who lost the bank more than $6.2 billion (£4 billion).

The warrant, understood to have been sent to Scotland Yard, has been issued by New York prosecutors. No arrest has been made, and there are reports Martin-Artajo is on holiday.

Scotland Yard declined to confirm that a warrant had been received. A spokesman said: “We are not prepared to discuss any requests for extradition.”

Julien Grout, a former trader who worked alongside the Whale, Bruno Iksil, is also said to be about to be arrested. He recently moved back to his native France, from where it may be harder for the US authorities to extradite him. His lawyer denied he was on the run.

Martin-Artajo was Iksil’s supervisor while Grout helped in valuing his trading book in the London offices of the bank, where the losses were uncovered. The two are expected to be charged with trying to conceal the scale of the losses. Iksil is understood to be co-operating with the US authorities and is not expected to be charged.