Hoax call to David Cameron prompts security review

‘Downing Street says it is to review security procedures after a hoax caller was put through to Prime Minister David Cameron.

Number 10 said the caller claimed to be Robert Hannigan, director of government monitoring agency GCHQ.

Mr Cameron ended the call when it became clear it was a hoax and no sensitive information was disclosed.

GCHQ is also conducting a review after Mr Hannigan’s mobile phone number was disclosed during an earlier hoax call.’