A driver who was killed while swerving to avoid a crash on the M20 had been smoking cannabis before he got behind the wheel.

David Fowler, 30, died of head injuries when his Ford Focus flipped onto its roof and smashed into a tree on the London-bound carriageway, an inquest in Folkestone heard.

The former Norton Knatchbull pupil, from Willesborough, was trying to avoid a Ford Focus that had crashed into the central reservation a few minutes previously after driver Joanne Phillips lost control, possibly due to a burst tyre.

Miss Phillips, from Folkestone, fought back tears as she told coroner Rachel Redman she stood by the statement she gave police after the accident on the evening of February 15.

She said the steering wheel was "ripped out of her hand" and she spun twice, hitting the central reservation as she fought to regain control.

Miss Phillips said the next thing she knew Mr Fowler's car "came out of nowhere" and "just flipped".

Police interviewed Miss Phillips under caution after Mr Fowler's death, but did not charge her with any offence.

"A theory called 'look but don't see' in which drivers take longer to react to hazards they are not expecting to see..." - one theory heard at the inquest

Pathologist Dr Nippin Bagla said Arsenal fan Mr Fowler, of Sprotlands Avenue, had died due to his head injuries - but revealed the driver had smoked cannabis both a few hours before the crash and a while before that too.

The doctor told the inquest the drug "may have affected his driving capability".

Collision investigator PC David Burley said police were unable to prove a blown tyre caused Miss Phillips to lose control, but said it was a possibility.

He said her car's hazard and rear lights were on when Mr Fowler, an accountant and amateur DJ, drove up behind it.

PC Burley agreed the cannabis could have affected Mr Fowler's judgement and also mentioned a theory called "look but don't see" in which drivers take longer to react to hazards they are not expecting to see - for example, a stationary car in the fast lane of the motorway.

He said visibility was about 400 metres on the evening of the crash - despite it being dark - and believed Mr Fowler had been in the fast lane when he started to swerve around the other car.

A number of people stopped to help Mr Fowler and Miss Phillips, including Louise Cooney, from Rochester, and Ashford man Andrew Duncan.

Miss Cooney saw Miss Phillips crash in front of her, just after 9pm near junction 9, and said it appeared as if one of her rear tyres "sort of deflated" before she spun into the barrier.

Mr Duncan said several vehicles "went thundering through" before Mr Fowler's crash and managed to avoid Miss Phillips' car.

Both witnesses and Miss Phillips tried to help Mr Fowler, but they could not get into his car.

Mrs Redman concluded Mr Fowler's death was accidental and praised everyone who stopped to help both victims.

When the inquest finished, members of Mr Fowler's family hugged Miss Phillips as she sobbed.