The motorcyclist is said to be aged in his early 20s and was wearing light grey tracksuit bottoms with a double light blue stripe down each leg, a black jacket and black gloves which had plastic caps on the knuckles. He was also wearing a green and silver crash helmet.
The bike he was riding is described as a black and green off-road machine with Evo-Tech written on the front shocks.
More top news
Philippa has the latest weather for the east
Philippa has the latest weather for the west
Charges against Oxford University student Oliver Mears were dropped days before his trial.