A fourth man has been arrested in connection with the death of a man at a property in March.
Police were called to the incident in Creek Road, March, on Wednesday (18 April) evening.
A post mortem examination found the man had significant head trauma, however, the cause of death remains unexplained. Further forensic tests will now be carried out.
The 38-year-old man from March has been arrested on suspicion of murder and is in custody at Thorpe Wood Police Station in Peterborough.
Three people, two men aged 35 and 53, and a woman aged 42, who were arrested on suspicion of murder, have been released under investigation.