A teenage driver who killed two car passengers in a crash after a convoy of "boy racers" reached 100mph has been jailed for four and a half years.

Gary Nicholson lost control of his Vauxhall Corsa as he hit speeds approaching 100mph and skidded across the road before colliding head-on with a Peugeot 206 driven by John Brown.

Mr Brown's wife Patricia was pronounced dead by paramedics after the crash and a passenger in Nicholson's car, 18-year-old Alec Stewart, later died.

The High Court in Edinburgh was told in December that another motorist saw 64-year-old Mr Brown at the grass verge after the collision and heard him say: "What have these boys done?"

Peter Shaw had earlier been overtaken by a succession of vehicles and said to his wife Caroline: "Boy racers, I'll let them get by."

Nicholson, now 20, admitted causing the death of 52-year-old Mrs Brown and Mr Stewart, both of Stewarton, East Ayrshire, by driving dangerously at grossly excessive speed causing him to lose control and crash on April 20 last year on the B769 between Stewarton and Irvine.

Three others, 20-year-old students Ewan Alvarez McLeod and Yung Lau, both of Stewarton, and 23-year-old soldier Lee Copeland, formerly of Irvine, admitted driving dangerously at grossly excessive speed.

They avoided a prison sentence at court on Friday. Lau was ordered to carry out 142 hours of unpaid work, while Alvarez-McLeod and Copeland got 300 hours' unpaid work.

Advocate depute Alex Prentice QC told the court in December that the accused and others met in a car park at Sainsbury's supermarket in Stewarton and were planning to travel to a "car cruise" event in Irvine.

Copeland attached a camera to a passenger window of his Volvo to record the vehicles in convoy and footage from it was shown to the court of the journey and the aftermath of the crash.

The prosecutor said the cars driven by Lau, Nicholson and Alverez McLeod pulled away from the group and overtook Mr Shaw, who was travelling at about 40mph with his wife and young child. Mrs Shaw said they overtook "nose to tail". About 20 seconds later Copeland also overtook the couple.

Mr Prentice said: "Nicholson continued to drive and at excessive speed behind Lau. Alvarez-McLeod continued to drive closely behind Nicholson, also at excessive speeds.

"Copeland, also driving at excessive speeds, brought up the rear a short distance behind him. It is apparent from the camera footage that all four intended to keep the convoy intact."

Investigators said all three vehicles in front of Copeland's car at the moment he approached the collision site "must have been travelling at speeds approaching 100mph for a period of time".

Mr Prentice added: "Nicholson lost control of his vehicle due to his excessive speed and the vehicle fully crossed over the centre lines, onto the opposite carriageway, directly into the path of Mr Brown's vehicle."

Brown said he became aware of the Corsa "skidding across the road" with "smoke belching from the wheels".

He performed an emergency braking procedure but after the collision Nicholson's car then hit a tree and went into a field.

Alvarez-McLeod swerved to avoid the crashed vehicles and his car went on to its side. He managed to climb out and made a 999 call.

Mrs Brown, who was returning from a short weekend break, was trapped in their car and died at the scene after suffering head injury.

Nicholson's Corsa ended up in a field at the side of the road. It started smoking before going on fire. His passenger, Mr Stewart, died from his injuries.