Two people have allegedly been threatened with a blade at Kempton Park racecourse in Sunbury.

Police are investigating reports of an aggravated robbery at around 2pm last Thursday with the victims told to hand over jewellery.

Police said the driver of a getaway vehicle is described as a white man, in his early twenties, of slim build and with sandy blonde hair.

Any witnesses or anyone with information or dashcam footage is urged to contact police on 101.