The robbers’ victims Michael Irvine and Louise Cogle described how they feared for their lives.

Social worker Miss Cogle, 38, said: “I have never experienced such a fear in my life. Afterwards my body was trembling and my legs were wobbly. It went on for hours.”

She was signed off work for two weeks and was offered counselling by her employer Shetland Islands Council and Victim Support.

The mother-of-three said: “I felt fragile for weeks, and couldn’t tell the story without breaking into tears.”

Mr Irvine, 49, a foreman at the Shetland Catch fish factory, said it felt “surreal” and “like a movie” to be caught up in such a life-threatening scenario. He said: “Police officers told us we were lucky to be alive – and that is all we were caring about.”

Miss Cogle said they had no reason to suspect that anything was untoward. She had done a vehicle history check on the DVLA’s website and had been in regular contact with the seller.

They were re-directed to another address when they arrived in Bradford where three men, wearing balaclava masks, charged out of a driveway shouting: “We are going to shoot you. Where is the money?”

They held the gun at Mr Irvine’s face. MIss Cogle said she was terrified when she heard one of the attackers releasing the gun’s safety catch.

They were disturbed as a grey BMW approached and Mr Irvine said: “They grabbed the suitcase with the money in it and ran away. It was totally opportunistic, as they did not know that we had £5,000 with us.”

The cash and their passports have not been recovered.

Miss Cogle said: “At least we are alive. You would never wish such a thing happening to anybody.”