Humberside Police are appealing for a Good Samaritan who detained a man attempting to rob a Scunthorpe supermarket to come forward.
A man threatened the shopkeeper at the H&S store on Rowland Road at 5am on Tuesday, October 10, demanding money from the till.
As the man fled he was detained by a member of the public until the police arrived.
A 47 year-old man has been arrested on suspicion of robbery and remains in custody.
A police spokesperson said: “We would like to speak to the Good Samaritan that assisted in detaining the suspect before we arrived on the scene, he left before we could take a statement from him.
“If this was you or if you have information that would help with our enquiries please call us on 101 quoting log 49 of today (October 10).”