A woman who was killed after her car crashed into a tree died after suffering multiple injuries, an inquest found today.

Collette Mead died at the scene when her black BMW Mini came off the M25 slip road to the London-bound M40, at J16, and careered into a “substantial” tree on July 3 this year.

The court heard the 59-year-old, from Watford, could have suffered a medical episode prior to the accident, but there was no evidence found by the pathologist to suggest this was the case.

The inquest was also told some “vegetable matter” was found in her lungs, suggesting some sort of aspiration from “food or stomach content” either before the incident or as a result of the impact of the crash.

Analysis of her two mobile phones – work and personal – found she had made 21 outgoing calls in the 15 minutes before her accident, leading police to suggest she may have been distracted from the road in the minutes before she died.

Eyewitness Marian Baroianu said he saw Mrs Mead’s car leave the motorway and crash shortly after, adding she did not seem to be speeding.

In a police statement read out to the court, he said: “I was driving on the M25 at around 10am that day. I left at J16 to go towards London.

“There was one car in front of me about 100 metres away. It didn’t drive around the bend [on the slip road] and went straight into the bushes.

“I was travelling at 50 miles-an-hour and the other car was travelling at around the same.

“I stopped my car safely where I was able to do so and ran across to check on the driver.”

Mr Baroianu said Mrs Mead was leaning to the side with her seatbelt on, adding: “The car was completely destroyed.”

He said Mrs Mead did not respond to him so he called 999 and checked for a pulse but could not find one.

He also said he did not see Mrs Mead put the brakes on her car or attempt to swerve.

The vehicle examination report found there were no issues with the car that could have caused the crash, while the road was found to be dry and visibility good on the day.

Police found two mobile phones in Mrs Mead’s car and analysis of the phones found she had made around 19 calls from her personal phone, which was found to be connected to her in-car entertainment system via Bluetooth, and two calls from her work phone which was not found to be connected to the hands-free system.

A collision investigation report suggested this was “likely to have diverted her eyes or attention from the road”.

The court was also told there were no crash barriers where Mrs Mead had her accident, with senior coroner for Buckinghamshire Crispin Butler saying it was “unfortunate” the crash barrier had ended just before where Mrs Mead’s car came off the road and into the tree.

South Central Ambulance Service said paramedics tried to revive Mrs Mead but she was sadly pronounced dead at the scene.

Mr Butler said there were three possible scenarios – a possible medical episode, such as a blackout or seizure, an event involving some aspiration of food content, like coughing something up, that could have occurred immediately before, and her use of her mobile phones that could have caused her to become distracted.

He said some of the calls made from her phones were very short, suggesting they could have been accidental dial-outs or cut off before they were answered.

But, he added, on the balance of probabilities there was no way to say her use of the mobile phones was the only reason for the crash as there was “no reaction, no brakes, no deviation at all” by Mrs Mead.

The medical cause of death was given as multiple injuries from a road traffic collision and Mr Butler recorded a conclusion of a road traffic collision, adding: “We are lacking the cause of the vehicle leaving the road.”