LONDON — US investigators conducting a criminal probe of interest-rate manipulation have asked their British counterparts for permission to interview London traders, two people familiar with the investigation said.
The Department of Justice filed a request with the British Home Office for access to dozens of bankers in conjunction with British prosecutors who are also investigating the rate rigging, said one of the people, who declined to be identified because the proceedings have not been made public.
The move may indicate the United States wants to pursue criminal charges against individuals in Britain that could lead to extradition, said Bradley Simon, a former federal prosecutor in Brooklyn.
It ‘‘won’t deter them in the least’’ that British prosecutors are also involved, he said.
‘‘They don’t stay within US borders,’’ Simon said in a phone interview. ‘‘They don’t hesitate to charge non-US citizens abroad and I know that this case is being investigated within the antitrust division of the Justice Department, which is known to take their cases very seriously.’’
‘They don’t hesitate to charge non-US citizens abroad.’
Regulators from Tokyo to London to New York are probing how derivatives traders and bankers who submitted interest-rate data colluded to rig benchmarks, including the London Interbank Offered Rate. Royal Bank of Scotland Group, UBS, and Deutsche Bank are among lenders awaiting information about their fate.
The Justice Department’s criminal probe is running in parallel with civil investigations being conducted by its fraud division, the US Commodity Futures Trading Commission, and Britain’s Financial Services Authority.
Britain’s Serious Fraud Office opened its criminal case in July at the request of British politicians after Barclays was fined a record $470 million for rate manipulation.
The agency had previously declined to get involved in the case, according to the Financial Services Authority. Barclays chief executive officer Robert Diamond and chairman Marcus Agius resigned following the fine.
A Home Office spokesman declined to comment on any cooperation request. A spokesperson for the Department of Justice did not immediately respond to a request seeking comment on cooperation with British authorities.
Extradition is a concern for suspects in Britain after three British bankers who faced Enron Corp.-related fraud charges lost a three-year court battle and were sent to the United States in 2006 to face trial. The men, who worked for Royal Bank of Scotland Group’s Greenwich NatWest unit, had argued that as British citizens accused of defrauding a British bank, any prosecution against them should have been in England.
It was among cases that prompted British lawmakers to say a 2003 extradition treaty with the United States was unfair and urged Prime Minister David Cameron to renegotiate it.
‘‘The UK courts have basically turned over for extradition just about anyone the US seeks,’’ Simon said.
Simon represented British lawyer Jeffrey Tesler, who was extradited to the United States last year to face bribery charges. Tesler fought the extradition, saying because the case had strong links to the UK and British prosecutors were carrying out their own investigation, he should not be sent across the Atlantic.
If the Serious Fraud Office files ‘‘almost identical’’ charges then the courts may deter extradition, Simon said, while if the United States files antitrust charges and the Fraud Office charges traders with fraud or false accounting, an extradition may still happen.