Police are investigating a suspicious incident, near to the car park for Lidl at Charlotte Street, Carlisle, reported at about 7.30am on November 15.
A Police spokesperson explains: "It was reported that a blood-stained knife, along with a t-shirt and trainers, were on the footpath near the car park.
"Upon forensic investigation, no blood was found on any of the items. Police are treating the incident as a possible offence of wasting police time."
Officers are appealing for anyone with any information to contact PC 2531 on 101, referring to incident 38 of November 15.