A masked Boston robber was filmed wrestling with and threatening a shopkeeper to steal cash from her till.
CCTV cameras show that a man went into the Baltic Shop on Carlton Road at around 11.21pm on Tuesday, March 3.
He made threats to the shopkeeper and forced her to the till. He made off from the store with cash, possibly on a pushbike, police said.
The suspect is described as wearing a black puffa jacket and distinctive black tracksuit bottoms with white details on the inside bottom half of the leg.
Both his face and his head were covered, but police have asked for anyone with information to come forward.
Anyone who has CCTV or dashcam footage of the area should call 101 and quote reference 485 of March 2.