A computer generated image of a man wanted for an attack on a woman in her home has been released by officers investigating the case.
The man was one of two who knocked on the door of a house in Farnborough Drive, Daventry, sometime between 9.45pm and 10.15pm on Wednesday, December 16.
They asked the woman for money but she refused and tried to close the door.
Both men then pushed the door open, knocking the woman to the floor.
The woman was then attacked by one of the men, leaving her unconscious and with facial injuries which needed hospital treatment.
The men then stole money from the kitchen and fled.
Both men were white, in their mid-to-late 30s and are thought to have been eastern European.
The first man was of medium to stocky build, about 5ft 8in with dark cropped hair. He had a strong accent and was wearing a light-grey hooded cardigan which had a zip down the front.
The second man was of slight to medium build, was under 5ft 8in and had mousey brown, collar length, hair which was messy.
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.