A pub landlord in Essex was threatened with a knife by a raider who went into his office last Wednesday.
A five figure sum of cash was handed over in the robbery at the Plume of Feathers pub in Church Hill, Loughton.
The robber is described by police as white, 5ft 10in tall, of stocky build, wearing a black balaclava and dark clothing.
He escaped in the landlord's Vauxhall combi van which was found abandoned later under the M25 at Waltham Abbey.
Police would like to hear from anyone who may have seen a man entering or leaving the pub that morning.
They would also like to hear from anyone who may have seen the van being abandoned under the motorway, later that day.