A woman was found dead at her home five days after police went to the address following an emergency call, a watchdog said today.
Officers went to Rosalyn Hunt's flat in Ipswich, Suffolk, on 4 August after being told that a woman was in distress, said the Independent Police Complaints Commission (IPCC).
Police had knocked on the door and checked the property but could obtain no response - then on August 9 Ms Hunt, 41, was found dead inside, said an IPCC spokesman.
The IPCC said police returned to the flat five days later after a neighbour raised concern and said she had not seen Ms Hunt for three days.
Officials said police forced their way into the flat and discovered that Ms Hunt had died after sustaining serious chest and neck injuries.
The IPCC said it had launched an investigation into the actions of officers who responded to the 999 call.
The spokesman said Suffolk Police had referred the incident to the IPCC.
"We will examine whether the officers did all they reasonably could to establish whether anyone was at risk within the property when they attended the address on 4 August," said IPCC commissioner Rachel Cerfontyne.
"We will also consider whether on the basis of the information available any subsequent visit to the flat should have been actioned by police themselves or other follow up inquiries made."
The IPCC said three people had been charged with Ms Hunt's murder.