Westminster terror attack a 'wake-up call' for encrypted messaging firms

The Westminster terror attack was "a wake-up call" to companies who run encrypted messaging sites, Britain's top cop has said.

Craig Mackey, acting Metropolitan Police Commissioner, told London Assembly members: "This is a wake-up call for the industry to understand what it means to put your own house in order.

"If you talk about working ethically, it has to mean something."

Mr Mackey was responding to questions from the assembly's Police and Crime Committee a week after the terror attack in which Khalid Masood ran down and killed three victims and fatally stabbed PC Keith Palmer at Parliament.

Masood, 52, had been using the encrypted mobile messaging service WhatsApp a couple of minutes before he launched his deadly attack.

Detectives are struggling to get access to his WhatsApp activity as they try to understand his motive and identify any associates.

Mr Mackey revealed police had up to 3,500 witnesses to the attack, which began on the south side of Westminster Bridge and lasted 82 seconds, before Masood was shot dead by an armed police officer.

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He told the committee a "truly enormous" volume of digital information is being examined as part of the investigation.

Mr Mackey added: "It's a challenge when you are dealing with companies that are global by their very nature because they don't always operate under the same legal framework as us."

Assembly members also quizzed Mr Mackey over concerns about funding and whether the Home Office would pick up the bill for the initial police response and investigation.

Mr Mackey said: "As the officer in charge last Wednesday, I never thought about money."

WhatsApp has said it is "co-operating with law enforcement as they continue their investigations".

It comes ahead of a meeting between Home Secretary Amber Rudd and technology bosses on Thursday.

Facebook, Google and Twitter are among companies that have repeatedly faced calls to do more to detect and remove jihadist and other extreme videos and web pages, with Foreign Secretary Boris Johnson attacking a "disgusting" failure to remove it at the weekend.

Twelve people have been arrested in connection with the Westminster attack.

Two remain in custody, one has been released on bail and nine have been released with no further action.

An inquest for the victims - Kurt Cochran, 54; PC Keith Palmer, 48; Leslie Rhodes, 75 and Aysha Frade, 44 - will be opened at Westminster Coroner's Court later.