A 96-year-old woman was held back by a thief while three of his accomplices stole cash after forcing their way into her house in Kettering.
The woman was at home in Byron Road between 7.45pm and 7.55pm on Monday (February 8) when she heard persistent knocks and the doorbell ringing at her front door.
She went to her door and asked who it was and one of the men asked to be let in.
But she refused and told him to go away.
The man then stated that he was from the water board and demanded to be let in.
They then used some sort of tool to force open the door and four men pushed their way in.
Once inside, one of the men physically restrained the victim by holding her arms, causing bruising.
They searched the house and stole a large amount of cash.
The first offender is described as about 6ft, clean shaven and of stocky build.
He appeared mucky, with a possible foreign accent but spoke good English.
He wore black gloves and a khaki green jacket.
The second offender was young, of skinny build and between 5ft 10in and 6ft.
He wore black gloves and had a black scarf covering his face.
The third offender had a black scarf with a blue stripe across it, covering his face.
The fourth offender had a black scarf with a green stripe across it, covering his face.
Officers are asking anyone with any information to urgently call the police.
They would particularly like to speak with anyone who may have CCTV in the following roads: Byron Road, Bath Road, Scott Road, Weekly Glebe and Northfield Avenue.
Anyone with any information can call Northamptonshire Police on 101 or they can call the independent charity Crimestoppers anonymously on 0800 555111.