A driver was speeding and swerving moments before he and seven others died in a crash on the A23, an inquest heard today.

Witnesses said the BMW driven by Mitch Treliving, a 19-year-old glazier, was overtaking cars that were travelling at more than 75mph on the stretch of the A23 at Pyecombe, near Brighton.

Mr Treliving, of Tilgate Parade, Crawley, had used cannabis at some stage before the crash but pathologists could not say precisely when.

The BMW saloon, in which there were four passengers, crossed the central reservation and ploughed into an oncoming Land Rover Freelander.

All five in the BMW and three people in the Freelander, including a two-year-old boy, were killed in the crash on May 16 last year, described as the worst in living memory in Sussex.

Those killed in the BMW were Mr Treliving, Aaron Sharpe, 20, his sister Katherine, 18, of Gossops Drive, Crawley, Gemma Smoker, 17, of Henshaw Close, Bewbush, and Danielle Billingham, 17, who had just moved to Crawley.

Those who died in the Freelander were Kate Beasley, 30, her husband Toby, 33, and two-year-old Marcus Mohabir, all from Godalming, in Surrey.

Relatives of the dead, some in tears, listened as coroner Roger Stone explained it was his sad task to determine how they died but it was not his job to apportion blame for the catastrophic and devastating crash.

Pathologist Dr Patricia Beresford told the inquest in Worthing how all eight had died from multiple injuries and some had also suffered severe head traumas.

Tests on Mr Treliving, she said, showed an almost negligible amount of alcohol in his body but, she said, at some point he had used cannabis.

Motorists testified how they saw the BMW driving dangerously before the crash.

Jan Warrington, from Horsham, said he was driving his Citroen Saxo at Handcross at 60mph when he saw the BMW driving just inches from the vehicle in front of it. The driver was chatting to the front seat passenger.

He said: "I felt in immediate danger. I wanted to let him know but I would have caused more trouble if I had beeped my horn."

He next saw the car in a lay-by at Bolney. One man was out of the car using his mobile phone, looking back down the road as if searching for someone. It was only when Mr Warrington reached work in Brighton that he heard about the crash.

He realised he had seen some of the victims, two men and three women, laughing and happy just minutes before the crash.

Stuart McLean saw the BMW in the rear view mirror of his Renault Scenic. He said the car was very close behind and his wife started to get distressed, shouting at him to move into the inside lane.

Mr McLean said: "If I had braked at all he would have hit me, without a shadow of a doubt."

Mr McLean moved into the inside lane. He said he was doing 60-70mph and the BMW was going faster. He saw the BMW overtake and then regularly undertake other vehicles ahead.

Edmond O'Toole was driving his VW Golf on the first sunny weekend of the summer. He was doing between 70mph and 80mph when the BMW came up behind him. He said he noticed the BMW wobble because it was going so fast. He was alarmed and nervous so he pulled over to the slow lane. He described the BMW as almost out of control.

The hearing continues.