A robber forced staff at a Kettering bookmakers to hand over cash at gunpoint in an armed raid on Monday night.
The robbery happened at about 9.25pm at the Coral bookmakers in Montagu Street.
A spokesman for Northamptonshire Police said: “A man entered the shop carrying a small black handgun and a bag and demanded money.
“A member of staff handed over a quantity of cash and the man left the shop.
“He was seen to run away from the shop down Tresham Street.”
The offender is described as between 6ft 2in and 6ft 3in, with a heavy build.
He was wearing a black hooded top, white gloves and a black scarf.
The Telegraph contacted Coral but was told the firm did not wish to make a comment.
The robbery comes just a few weeks after two shops near Coral were targeted by a pair of robbers armed with a shotgun.
The two tried to rob a Tesco Express store in Windmill Avenue at 12.15am on Friday, December 20, and then the Co-op food store in Stamford Road at 6.30am on Monday, December 23.
However, the Co-op robbery was foiled when the manager of the shop was able to lock the doors.
The manager at Tesco also stopped the robbers when he locked himself in a toilet block inside the building.