A suspicious package sent to former MSP Trish Godman's constituency office could have exploded under the correct circumstances, a court has heard.
Royal Navy bomb disposal expert Chief Petty Officer Lee Yates told the High Court in Glasgow that a liquid inside a plastic bottle within the package had tested positive for the explosive substance tri-acetone tri-peroxide (TATP).
He said the liquid would normally be ignited with a power source such as a battery, but said it could have been triggered by light energy as the envelope was pulled open.
Mr Yates was giving evidence at the trial of Trevor Muirhead, 43, and Neil McKenzie, 42, who deny plotting to murder Celtic manager Neil Lennon, as well as Ms Godman and lawyer Paul McBride QC, who are both supporters of the club, by sending improvised explosive devices to them.
The court heard that prior to the incident, Ms Godman, who was the Labour MSP for the West Renfrewshire constituency, had worn a Celtic top to the Scottish Parliament as a "dare for charity" on the final day before Holyrood was due to dissolve pending the election which followed in May last year.
A package delivered to her office in Bridge of Weir, Renfrewshire, on Monday March 28 sparked the evacuation of the building.
Mr Yates, 48, was asked by advocate depute Tim Niven-Smith if the device had the "general appearance" of an improvised explosive device, to which he replied: "Absolutely. Anyone opening that envelope would get quite a fright I would think."
He went on: "It could have been part of a learning curve. It possibly could have been developed further if it had been allowed to go on. TATP usually comes in crystal format, like sugar.
"It is much more potent like this, putting it through the postal system in that state - it is unlikely it would reach its intended destination. Liquid is added to TATP to make it more stable.
"If it functioned in the way it was intended it could cause serious injury or even death, particularly because it contained nails which would act as shrapnel."