A prank caller managed to get through to British Prime Minister David Cameron on Sunday, prompting a security review at 10 Downing Street.
The caller claimed to be Robert Hannigan, the director of the Government Communications Headquarters (GCHQ), a U.K. intelligence agency, according to the Guardian.
Another hoax was reported on Sunday when a caller managed to reach GCHQ and obtain the phone number of Hannigan.
A government spokeswoman said “Following two hoax calls to government departments today, a notice has gone out to all departments to be on the alert for such calls.”
The spokeswoman added that the phone call was “quite brief” and no sensitive information was disclosed.
Mr. Cameron has been duped before. In 2013 he tweeted at a spoof account for work and pensions minister, Iain Duncan Smith, without apparently realizing the account was a fraud.