A bin lorry driver accused of killing an 80-year-old stroke victim by reversing over his mobility scooter failed to take "adequate steps" to ensure the road was clear, a court has heard.

Scott Hamilton had to back up to give an oncoming Audi space to get by on a single track road at Sheriffmuir, near Dunblane, Perthshire, but he but did not use a "banksman" to check behind him before he did so.

Mr Hamilton, 44, was driving a Stirling Council lorry, emptying recycling boxes, when the incident occurred on December 3, 2014.

The High Court in Stirling heard that he put the lorry into reverse after asking his assistant, Lee McEwan, to check the nearside mirror - but neither of them noticed that retired teacher Peter Wills, 80, who used his scooter daily to watch wildlife and red kites near his home on Sheriffmuir, was behind them.

Mr McEwan, 20, said the 7.5 tonne truck collided with Mr Wills' scooter with a "thud".

He said they had passed Mr Wills a little earlier and he immediately realised what had happened.

He said: "We had to reverse to give the Audi space to get through.

"Scott just says if I could see anything in my mirror and I said 'no' and he put the motor into reverse.

"It was just a split second thing. He put it into reverse and then it just happened.

"We assumed there was nothing there. We went back a few yards and then we heard the thud.

"Obviously I had seen him [Mr Wills] at the bottom of the road, and that was the first thing that came into my head."

Mr McEwan said Mr Wills' scooter was lodged between two beams at the back of the lorry and Mr Wills was on the road with "blood gushing out of his head".

He phoned 999 and Hamilton gave Mr Wills CPR until the emergency services arrived.

When paramedics got to the scene they found Mr Wills unconscious and with no pulse. They took over CPR until several doctors arrived by police helicopter, but they were unable to save him.

A post-mortem revealed he died of multiple broken ribs and a broken neck, which would have impacted his spinal cord and stopped him breathing.

Mr McEwan told the advocate depute Jane Farquharson that he had received training in the role of "banksman", or reversing assistant, from Stirling Council eight months earlier, but claimed that because the lorry they were using was "smaller than the normal recycling lorries" it did not need a banksman to reverse.

He said: "I wasn't asked to be a banksman on that vehicle -- I was just emptying boxes.

"If I was asked to be that, I'd have done that. I was only an apprentice at the time."

He added that after the incident he and Hamilton had "done their best" to try to save Mr Wills.

The driver of the Audi, Iain Dick, 60, said that at the point where he met the lorry, it was much easier for the lorry to reverse than it would have been for him.

Mr Dick said the lorry went back about two metres and he then heard a "grating sound".

He added: "It was obvious that there was something on the road that was being crushed."

Mr Dick said the bin lorry driver got out, went to the back of the lorry and came back looking "extremely agitated".

The Audi driver said he realised something serious had happened and got out and went round the back of the lorry himself.

He said: "It was shocking, something I had never seen in my life before and hope never to see again."

He said there were "the remains" of the scooter and Mr Wills lying on the ground "in very serious distress".

Hamilton was crying and said words to the effect of "I didn't see him, I didn't see him".

Earlier, Mr Wills' widow Virginia told the jury that her 50-year marriage to Mr Wills had been "paradise".

She said her husband had been left paralysed down one side and without speech after a stroke eight years before his death, but "revelled in his independence" and would spend up to two hours every day out on his electric scooter near their isolated home near Dunblane.

Hamilton, of Bonnybridge, Stirlingshire, denies causing death by dangerous driving.

He is said to have caused his lorry to collide with Mr Wills' motorised wheelchair in the incident on Sheriffmuir Road, near Dunblane, by reversing without taking adequate steps to ensure it was safe and the road behind him was clear, and without using and being guided by a trained banksman provided for the purpose.

The court heard that since the accident, Stirling Council recycling lorries had been fitted with sensors to warn their drivers of obstacles behind them.

The trial before Lord Ericht is expected to last several days.