BORIS Johnson’s phone was taken off him because MI5 feared the Prime Minister was a “massive security risk”, it has been reported.

The Tory leader hit the headlines in April when it was revealed that his private phone number was freely available on the web – and had been since 2006, when it was included at the bottom of a Tory press release.

Concerned Johnson would not comply with demands to change his number, MI5 ordered that the phone be confiscated within 24 hours, according to the Mail on Sunday. One source told the paper that agents feared a "massive security risk". 

Downing Street confirmed that the phone had been taken away but denied it was MI5 agents, stating merely that is it was “officials”.

Security chiefs were also said to be worried about the Tory leader potentially leaking highly sensitive information due to his habit of conducting business over WhatsApp.

READ MORE: Boris Johnson's phone seized due to MI5 fears of 'massive security risk'

The Prime Minister has previously come under fire after his messages to Jennifer Arcuri were leaked. The US businesswoman, who claims the pair had an affair, received £126,000 of taxpayers’ money in event sponsorships and grants.

Johnson has also been left red-faced after his messages to Dominic Cummings were released.

The PM’s former top adviser published messages last week, including one screenshot in which Johnson described Matt Hancock as “totally f****** hopeless” in an exchange about testing.

Number 10 has not disputed the authenticity of the messages but insisted the PM has full confidence in his Health Secretary.

READ MORE: Boris Johnson backs Matt Hancock despite 'hopeless' WhatsApp messages, minister says

Earlier this year, it was reported senior officials had called on Johnson to change his number because of concerns about how many people contacted him directly.

It was later revealed that his phone number was available online to anyone who searched for it.

Attempts to call the number were met with an automated message saying the phone was “switched off” and an invitation to “please try later or send a text”.

The Prime Minister’s use of his mobile phone had already been in the spotlight after exchanges with entrepreneur Sir James Dyson and Saudi Crown Prince Mohammed Bin Salman were leaked.