A murder probe has been launched after a 63-year-old man died in hospital, following an assault by three men posing as Border agency officials.
The man was attacked after answering his door in Highfield Road in Wellingborough, Northamptonshire, on Friday November 25, before being taken to hospital, where he died 17 days later.
His attackers, who were known to have visited the property between 8.45pm and 10pm, were wearing black and purporting to be from the Border Agency, police said.
It is unknown if the suspects were using a vehicle and officers are keen to hear from anyone who may have witnessed three people in the area at the time knocking on doors, or any other suspicious activity.
Detective Chief Inspector Adam Pendlebury said: "I would urge everyone in the local area to review any CCTV, doorbell or dash cam footage they might have which could help our investigation.
"No matter how small you think it is, let us know about it so we can review it.
"Specially trained officers are supporting the victim's family at this time and my thoughts are with them as they come to terms with this awful news.
"Officers from the Neighbourhood Policing Team will be patrolling the area today and anyone in the local area with any concerns is welcome to approach one of these officers who will be happy to help."
Witnesses, anyone with information or anyone with any pertinent footage should call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.
