The driver of a wildlife rescue ambulance was brought to a stop near Uckfield and then assaulted by a man who demanded drugs.
The ambulance was being driven along the A22 Eastbourne Road near Palesgate Common at around 11pm on Monday evening (October 15) when it was overtaken by a dark-coloured older-style hatchback.
It slowed down and put on hazard lights bringing the ambulance to a standstill.
Thinking that something was wrong, the wildlife rescue man got out of his vehicle, but was then assaulted and asked to hand over drugs from the vehicle.
However, the wildlife rescue ambulance does not carry drugs or medical supplies.
The suspect was described as white, 6ft, of proportionate build, with facial stubble and wearing dark clothing.
Detective Sergeant Julie Dow from East Sussex CID said: “This would appear to be an opportunist and very unusual attack, which has obviously left the victim very shaken.
“We would like to hear from anyone who may have seen the two vehicles in the Palesgate Common area on Monday evening, either driving or at a stop by the roadside. Please call Sussex Police on 101 quoting serial 1861 of 15/10.”