A cyclist was robbed on a path between Wescott Way and Newark Drive, Corby.
The incident happened between 1pm and 1.20pm on Friday (March 29).
The victim was riding along the path when he was punched off his bike and threatened with a kitchen knife.
The offender then rode off in the direction of Wescott Way on the victim’s bike.
He was white, roughly 6ft, slim and had bright blue/green eyes.
He was wearing a black hooded zipped sweatshirt, black Nike jogging bottoms, black trainers, black sports gloves and a black snood.
Anyone with information should contact Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.