A takeaway delivery driver was robbed after he was called out to a false address in Corby.
The driver was called out to Trent Street at about 9pm on Tuesday, August 4.
After he arrived, he could not find the house number he was given, so got out of his car to look for the property.
He was then approached from behind by a stranger who threatened him with a knife and demanded money.
After forcing the delivery driver back into his car, the thief then took a small amount of cash and ran away.
He was aged between 28 and 35, medium build, about 6ft, with brown hair.
He was wearing a black jacket, blue jeans with a white pattern on the thigh, and a hooded top.
Witnesses, or anyone who knows anything about this incident, can call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.