A 26-year-old man high on amphetamines was killed after he lay down in the middle of the M40, near Loudwater, and was hit by two cars, an inquest heard on Wednesday.

Wojciech Rubaszniak, from Poland, had just landed in the UK on December 10 and was being driven along the M40 when an argument erupted, and he began punching his friend from the back seat.

The driver was forced to pull over on the hard shoulder and Mr Rubaszniak, who had recently been dumped by his girlfriend, ran off along the side of the carriageway.

His friends then continued their journey, assuming he would be "picked up by police" but minutes later he was seen lying on the inside lane and run over by at least two cars, killing him instantly.

The inquest at Beaconsfield Coroner’s Court heard Mr Rubaszniak was travelling in the car with Bogusz Krupski and his friend when a violent argument erupted, sparked by a conversation about Mr Rubaszniak’s life in Poland.

Mr Krupski said: "In the car he attacked me and beat me. He hit me on the face many times. He tried to twist my arm. He tried to strangle me and the driver.

"It became very dangerous to drive since we were on the motorway so we had to pull over. I left the car and he followed me. He continued to beat me outside. I want to make it clear that he left the car himself.”

Taxi business owner Christina "Crystal" Jenkins, who ran Princess Cars of Princess Risborough, was driving along the motorway when she saw a body in the road. She swerved her car onto the hard shoulder, stopped and dialled 999.

Jacqueline Leadbeater was driving her white Audi convertible when she saw a man running down the hard shoulder and his arms and legs appeared “uncontrolled”.

Mercedes driver Taneesha Barker described seeing Mr Rubaszniak lying down in the hard shoulder at the side of the motorway.

She said: "As I pulled into lane one I saw a person in my headlights lay in the hard shoulder. I thought straight away that it was a man. I saw jeans and I thought a jacket and I thought I saw blonde hair.

"The man was laid on his right side with his head towards the driving side of the motorway. He was waving his arms and legs around, I thought it was to get someone's attention."

Pathologist Dr Nicholas Hunt carried out a post-mortem examination and wrote: "The toxiciologist is of the opinion that the deceased may have been under the influence of amphetamine at the time of his death."

The inquest heard a statement from Detective Constable Joanne Insley in which the inquest was told Mr Rubaszniak’s girlfriend has just spilt up with him, he had gambled a lot of money away while in Poland and was known to suffer mental health problems.

Crispin Butler, senior Coroner for Buckinghamshire, recorded a narrative conclusion and the cause of death as severe head injuries.