A further four people have been arrested on suspicion of murder after the death of a 73-year-old man.
David Morgan, also known to some as Davie, was found dead at his home in Brook Street, Raunds, Northamptonshire, in the afternoon of 8 October.
A 52-year-old man from Kettering, a 42-year-old man from Wellingborough, a 42-year-old woman from Kettering and a 42-year-old woman of no fixed abode, have also been arrested on suspicion of murder and burglary.
Northamptonshire Police previously arrested a 38-year-old woman from Thrapston on suspicion of murder before releasing her on bail.
Complex investigation
Det Chief Supt Rich Tompkins, of Northamptonshire Police, described the investigation as complex.
“We have a very large number of officers and detectives working around the clock on this case exploring all evidential opportunities including CCTV and doorbell footage and forensics,” he said.
“We have arrested four more suspects and they are in police custody. We want to reassure people that we do not believe there is a wider threat to the public in terms of this investigation.”
Six days prior to his death, on 2 October, Mr Morgan had reported being the victim of an assault to Northamptonshire Police.
Given he was in contact with the police in the days before his death, the force has referred itself to the Independent Office for Police Conduct.
“Our thoughts are with David’s family and friends at this deeply difficult time,” said Det Ch Insp Johnny Campbell after the police launched its investigation.
“We are working at pace to establish the circumstances of David’s death and I would ask anyone with information which could help us to please get in touch.”