Fresh fears over Government security were raised last night as it emerged that Dominic Raab’s private mobile number has been available online for at least a decade. 

The Foreign Secretary’s contact details were discovered by a member of the public using a Google search, and appears to have been available since before he became an MP in 2010. 

The Foreign Office said on Tuesday Mr Raab’s number and other private information was swiftly removed once the department was made aware of the oversight.

The disclosure comes just weeks after Boris Johnson was forced to change his phone number after it was also found to have been available online for 15 years. 

The emergence of the Prime Minister’s number, which was subsequently shared widely online, followed days after The Telegraph revealed that he had been advised by the Cabinet Secretary, Simon Case, to change it. 

Senior sources told this newspaper at the time that Mr Case had been concerned that Mr Johnson’s number was too widely known. 

Lord Ricketts, a former UK national security adviser, told The Guardian on Tuesday night that the discovery of Mr Raab’s number highlighted the need for greater attention in Whitehall over the potential online security risks. 

"The wide availability of Mr Raab’s personal phone number must increase the risk that other states, or even criminal gangs, have been able to eavesdrop on his calls," he added. "It also means that anyone who happens to have had his phone number … is able to lobby the foreign secretary, bypassing the official channels which everyone else has to use. 

"Anyone taking on a role as sensitive as this should in their own interests pay as much attention to online as to physical security."

A Foreign Office spokesman said: "Private information was wrongly retained online, before the Foreign Secretary’s appointment.

"Once we were made aware, we had it removed immediately. Most of it was out of date, and no security was compromised."