Britain's most classified material is to be hosted in the cloud by Amazon after GCHQ struck a deal with the American tech giant, it has been reported.

       MI5 and MI6, will also use the system provided by Amazon’s cloud computing arm AWS to store secret data as part of the deal, according to the Financial Times.

       All the agencies’ data will be held in Britain and Amazon will not have access to information stored in the system, according to reports.

       However, concerns are likely to be raised about the privacy and sovereignty implications of such material being hosted by a non-British company.

       The new data storage system will enable spies to share information from overseas more easily and enhance the use of speech recognition and other technologies.

       Industry experts suggested that the deal could be worth between ￡500m and ￡1bn over the next ten years.

       The high-security cloud system is also set to be used by other government departments such as the Ministry of Defence during joint operations with the intelligence services.

       Earlier this year, GCHQ outlined how it intended to use AI to protect the UK from state-backed disinformation campaigns and other cyber attacks.

       GCHQ said to the Financial Times that it would not discuss its business relationships with technology suppliers. AWS declined to comment.

       The news came as the head of GCHQ revealed that cyber attacks have doubled in the past year.