The National High-Tech Crime Unit, set up earlier this year to fight crime relating to information technology, said data stored on Tuesday may hold vital evidence about those responsible for the devastating attacks on the World Trade Center and Pentagon.
"By working swiftly to contact the communications service providers in the U.K., I hope that we will be able to offer valuable assistance to U.S. authorities in investigating the appalling events of recent days," said Detective Chief Superintendent Len Hynds, head of the London-based unit.
The unprecedented request was made under Britain's Data Protection Act, which normally prohibits companies from keeping such data any longer than is needed for billing purposes.
A spokeswoman for the crime unit said the request was merely precautionary, to ensure that important data recorded on the day of the attacks, such as text messages, e-mails and voice messages, were not destroyed.
"We are not looking for anything in particular," said the spokeswoman, on condition of anonymity. "Communications are routinely destroyed after 48 hours. This safeguarding of communications data is to ensure that any potential data is saved should it be required for evidential purposes."
Saved information could only be accessed by law enforcement agencies, if specific legal authority were granted, the spokeswoman said.
The move falls short of steps taken by the FBI in the United States, which is serving search warrants to major Internet service providers in order to get information about an e-mail address believed to be connected to Tuesday's terrorist attacks.
Hynds said the cooperation of the telecommunications and Internet industry in Britain was voluntary.
"The decision for industry to assist us is entirely at their discretion and we will not therefore be asking for confirmation of support."
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