THE only British soldier to be killed fighting Isis was hit by friendly fire and not a roadside bomb, the Morning Star can exclusively reveal.

Sergeant Matt Tonroe tragically died last March while on a joint operation with US special forces to capture an Isis terrorist in Manbij, northern Syria.

A US commando, Master Sergeant Jonathan J Dunbar, was killed in the same incident.

The Pentagon released a statement days after their deaths blaming the blast on an “improvised explosive device (IED)” that detonated near their patrol.

But that version of events, which was widely picked up by journalists on both sides of the Atlantic, now appears to be wrong.

An internal probe — never before reported — has found no evidence that an IED killed Sergeant Tonroe.

Instead, officials believe he was killed “as a result of a detonation of explosives carried by a colleague.”

Investigators could not determine exactly why these explosives went off accidentally, and were unable to rule out one deeply troubling scenario:

That a grenade carried by another coalition soldier could have killed both men.

Investigators picked out more than half a dozen reasons why a roadside bomb could not have caused the blast. 

These included:

— Chemical samples that were consistent with “military grade” and not “home made” explosives

— An absence of IED components

— There was no blast crater

— Soldiers were injured from one direction only — an IED would have produced more fire damage and wounds from different angles

— Civilian activity in the area did not suggest there was a roadside bomb.

Officials concluded there was “a preponderance of evidence that the cause for Sgt Tonroe’s death was as a result of a detonation of explosives carried by a colleague during combat operations.”

Among the possible causes they identified was the “inadvertent detonation of a grenade or similar system.”

This shocking revelation will cause concern among politicians in both London and Washington, where the Pentagon has not corrected its initial statement about a roadside bomb.

Labour MP Lloyd Russell-Moyle told the Star that Parliament needed to have oversight of the special forces, which are currently exempt from the defence committee.

He said: “Our spies and secret services have oversight in the intelligence and security committee but for some reason our special forces are treated as second-class citizens and considered not worthy of oversight.

“This tragic case further highlights the importance of such oversight, to ensure lessons are learnt when missions go wrong.”

Afghan war veteran Joe Glenton was also concerned about excessive secrecy around British special forces.

“This again raises concerns about the abuse of Britain’s ‘no comment on special forces’ convention, which lags behind many of our key allies,” he told the Star.

“It is time for a War Powers Act, [and] a new level of transparency.”

He demanded that the “tax-paying public should know how our elite troops are being used.”

Tonight an MoD spokesperson confirmed to the Star: “It was initially believed that Sgt Tonroe was killed by enemy action.

“However, subsequent investigation concluded that Sgt Tonroe was killed by the accidental detonation of explosives carried by Coalition forces. 

"Our thoughts continue to be with Sgt Tonroe’s family and friends.”

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