Det Sgt Jack Gibbs, of Derbyshire Police, said officers were “working around the clock on this string of robberies”, which now number eight attacks on off-licences and smaller shops, after a new incident in Oakwood on November 7.

He said information provided by a member of the public led to an arrest for conspiracy to commit robbery, the suspect has since been released on bail and appealed to the public for their help.

“The offender (acts) quite calmly, targets shopkeepers with a knife and forces them to exchange cash and any consumable goods they can get their hands on,” he said.

“One of the good things that we have is that we have some really good quality CCTV that covers every crime and through that there are some really key and consistent features about how this offender goes about his crime.

“Certain aspects are his gait, his constitution, the way he carries himself, the communication he has with crime dealers and there are certain other lines of inquiry that we’re really interested in that are consistent throughout.

“We’re really confident that someone in the community has that crucial piece of information that we need.”

Additional reporting by Owen Shipton.