French Foreign Legion soldiers during an operation near Kabul,Afghanistan
French Foreign Legion soldiers during an operation near Kabul,AfghanistanReuters File

A day after France announced its multimillion plan to boost its counter-terrorism measures, reports have emerged that dozens of its highly trained soldiers from special forces and foreign legion may have joined the Islamic State (ISIS).

An unidentified defence ministry source confirmed to AFP that the government had information that its former soldiers have joined hands with jihadi elements.

"We estimate about a dozen former troops have joined these networks," the source said. "Our concern is not former soldiers... It's preventing the phenomenon of radicalisation within our forces."

Defence minister Jean-Yves Le Drian refused to comment directly on the reports. He, however, told the press that the cases of former soldiers joining jihadist groups such as ISIS are 'extremely rare.'

Following the reports on soldiers joining ISIS ranks, it has emerged that the military intelligence will be recruiting another 65 staff to add to its 1,000 men unit to vet and track recruits applying for special forces and foreign legion.

There are fears that the rogue soldiers can turn their guns on their comrades, or may even use their skills in carrying out attacks on the French soil.

Earlier in the week, local reports claimed that several soldiers-turned-jihadists have joined ISIS as 'explosive experts' and another one was heading an ISIS unit.

The reports also have found that a paratrooper from the elite 1st Marine Infantry Parachute Regiment also has joined the jihadists elements in Syria and Iraq.