A senior government adviser has told the BBC that the authorities are not prosecuting many Islamic State volunteers, believing they should be reintegrated rather than punished.

Max Hill QC, who acts as the government’s Independent Reviewer of Terrorism Legislation, told Radio 4 that “we do have a significant number [of Islamic State volunteers] already back in this country who have previously gone to Iraq and Syria” — currently estimated at something over 400.

“That means that the authorities have looked at them, and looked at them hard, and decided that they do not justify prosecution, and really we should be looking towards reintegration and moving away from any notion that we’re going to lose a generation thanks to this travel.”

“But that’s fascinating,” responded the BBC presenter.

“Because there is a school of thought, isn’t there, that looks and these people and thinks, ‘Well hang on a second they’ve gone to a place where mass murders were being committed, they’ve gone there voluntarily, they’ve gone there presumably because they have some enthusiasm for what was happening there’ — it is odd to treat them as if they’ve committed no offence,” he said.

“And it’s not a decision that MI5 and others will have taken lightly,” responded Hill.

“But they have left space, and I think they’re right to do so, for those who … travelled out of a sense of naivety, possibly with some brainwashing along the way, possibly in their mid-teens … We have to leave space for those individuals to diverted away from the criminal courts,” he insisted.

Counter-Terror Chief: Europe Home to ‘More than 50,000’ Islamic Radicals — with up to 25,000 in UK

https://t.co/VM35UXDDPd — Breitbart London (@BreitbartLondon) September 1, 2017

Having previously played Devil’s Advocate, the presenter appeared to accept this at face value.

“That’s a thoroughly interesting one isn’t it Richard Barrett,” he said to his other guest, a former MI6 global counter-terrorism director. “Actually, surprising numbers, possibly, of these people, are actually not necessarily a danger to us.”

“I think that’s absolutely right,” agreed Barrett. “Many of them, I think, went to join something new, something that looked bright and attractive … and came back highly disillusioned,” he suggested.

Hill conceded that there was no doubt that some of the people in question will have carried out “the most serious criminal offences” in Iraq and Syria, but assured viewers that “in any case where there is evidence of that” they would appear before a criminal court.

How evidence of crimes committed in a jihadist-controlled warzone might be gathered was left unexplained, however.

Robust words from the former COBRA committee member and Afghan task force commander https://t.co/y2zBDfhlIo — Breitbart London (@BreitbartLondon) May 27, 2017

Voices calling for more robust action against foreign fighters were absent from the discussion, with no-one to represent the popular view put by figures such as Colonel Richard Kemp, the former commander of British Forces in Helmand, Afghanistan and COBRA Committee member who believes they should be banned from re-entering Britain and either prosecuted or interned if they manage to sneak back in, depending on whether there is evidence to charge them with offence or not.

Max Hill’s assertion that the authorities will have “looked hard” at the hundreds of former Islamic State volunteers thought to be back among the general population also went unquestioned, despite London mayor Sadiq Khan recently confessing that the roughly 200 thought to be at large in his city are not being monitored.

Former National Counter Terrorism Security Office chief Chris Phillips has also questioned whether or not the British authorities really have any idea how many of British nationals went to fight for the Islamic State, or how many have since returned.

“I don’t believe the UK knows how many people have left for Syria or indeed come back,” he said in

“There are many ways of getting back into the UK avoiding checks.”

Follow Jack Montgomery on Twitter: @JackBMontgomery