Armed officers were called to Murrayfield Stadium in Edinburgh during a Robbie Williams concert last June, after police spotted a number of hoodie-wearing individuals acting suspiciously outside the venue.
Security was on high alert at the gig, which took place just days after a bomb was detonated shortly outside an Ariana Grande concert in Manchester. The attack claimed the lives of 23 people and injured more than 500 others.
The incident at the Robbie Williams gig took place during the singer's encore, and was defused when the suspects were able to show accreditation proving they were plain clothes security guards hired by Williams.
They were employed to help prevent the sale of bootleg merchandise to the thousands of Robbie fans in attendance as they left the show, according to a report from Edinburgh Evening News.
Details regarding the incident were revealed at an events conference in Glasgow this week by Colin Rodger, who is head of event management at DF Concerts.
"I had decided, due to the climate at the time, that I would base myself in the police control room to make sure that the event went well," he said.
"Right at the end, when Robbie was performing his encore, I saw the police all watching the cameras fervently. They were focused on these guys standing on street corners.
"Suddenly, after every bit of planning we had done about profiling people and people acting suspiciously, we had a real incident on our hands.
"We had people on four street corners who fitted the bill. Nobody knew who they were. The alarmed police started to move in. It was a very, very wobbly movement in the control moment. I suddenly had a flash of inspiration that they could be the merchandisers' security guys. Luckily we had accredited them."
By the time the night's revellers were leaving the venue, the alert had been cooled and panic had been averted.