Two people being questioned about the murder of Stephen Davidson have been released.
Mr Davidson, 31, who was unemployed, was found dead at his home near Bangor, Co Down, on Sunday.
A spokesman for the police said the 49-year-old man and 61-year-old woman were released pending a report to the Public Prosecution Service. A 40-year-old man is still in custody helping police with their inquiries.
Earlier, detectives from the PSNI's serious crime branch, who are investigating the killing, charged a 30-year-old woman with a number of offences including conspiracy to pervert the course of justice and impeding police.
Mr Davidson's body was discovered by a relative on Sunday evening.
Detectives believe he may have known his killers and that he died as a result of a violent struggle.
The crime scene at Ballyholme Road had to be evacuated for a time this afternoon after the discovery of an unknown substance.
Police later declared the area safe.
A spokeswoman said: "Tests have been carried out on a substance found at the scene. These tests have established that the substance did not pose a risk to any individual.
"Police took this precautionary measure to guarantee the safety of all concerned."