Eighteen-year-old Katie Whitehead, of College Road, Hockwold, died last year when her silver Citroen Saxo left the road as she drove to her job at West Suffolk Hospital, in Bury St Edmunds.

At an inquest into her death in Bury on Friday, coroner Dr Peter Dean said the teenager's car had been the only vehicle involved in the accident, which happened at 6.30am on June 30, on the B1106, near the entrance to Brandon Country Park.

A post-mortem examination, carried out by consultant pathologist Dr Barrie Cottrell, showed the teenager died as a result of head injuries she sustained in the crash.

Police, who were alerted by two passers-by who stopped after spotting the car, found no defect in the vehicle and no fault in the road. But officers investigating the crash found tyre marks that suggested sudden harsh steering had caused the car to leave the road – and Katie's mother, Jane Denney, told officers her daughter would have swerved if an animal had run out in front of her.

"Looking at all the features, we are left with the possibility that she suddenly swerved the vehicle for a particular reason," said Dr Dean.

"We cannot say for certain, but the possibility is that there was some animal in the road that caused her to react in the manner she did, thinking about the other creature instinctively before her own safety."

At the time of the accident, Katie, a former Methwold High School pupil, was described by those who had known her as 'a very popular, beautiful girl'.

Recording a verdict of accidental death, Dr Dean said: "Our thoughts are with the family, friends and all those who were close to Katie."