A RETIRED senior army retired officer has said that some Scottish soldiers may have been shot in mercy killings in the horrific aftermath of Britain's deadliest rail disaster at Quintinshill, near Gretna, a century ago.

The crash involving a military train filled with troops, most of whom were from Leith, two passenger trains and two goods trains claimed an estimated 228 lives and left hundreds more injured.

Built largely from wood lit by gas-powered lamps, the troop train carriages became a raging inferno in the collision and accounts emerged of horribly-injured soldiers being shot to spare them any further agony as there was little sign of rescue services arriving quickly at the remote location.

There are no official army accounts of the alleged shootings on 22 May, 1915, but Colonel Robert Watson of The Royal Scots, has told makers of a documentary for BBC Scotland that despite the lack of formal documentation he believes that in a very few cases, perhaps only one or two, they might well have taken place.

Colonel Watson has been interviewed for Quintinshill: Britain's Deadliest Rail Disaster which airs on BBC Two Scotland at 9pm on Wednesday, 20 May, and will also be shown on BBC Four the following night, also at 9pm.

He said: "All those that could be rescued were rescued. Many of them had amputations carried out underneath burning carriages so that they could be rescued.

"But many, of course, were trapped in such a position that they couldn't be got out or else the fire had taken hold and they couldn't be got to.

"And of course since then we've heard stories of some soldiers being shot and some soldiers possibly taking their own lives. It's never been formally documented."

Referring to the reported shootings, he added: "My own personal belief is that it probably did happen, in a sense of compassion, of mercy killing. It's almost impossible, sitting here, to comprehend what it was like that morning."

Presenter Neil Oliver examines the investigation and trial of two signalmen, held entirely responsible for the tragedy, that took place afterwards. The documentary, produced by Finestripe for BBC Scotland, explores the series of mistakes that may have caused the collision and the part played by the train companies and the Government and determines whether the investigation would have come to the same conclusions if it were carried out today.

Dramatised reconstructions add to the compelling account of a tragedy which had a profound effect on several communities in Scotland and remains the deadliest in the annals of Britain's railways.