Stephen Davidson, 31, was found dead in the living room of his house in the Ballyholme Road area of the town on Sunday at around 5pm.
He died in what police described as a "violent struggle".
The area was evacuated on Thursday evening and specialist teams tasked to the scene as a precautionary measure, police said.
Tests were carried out which established the substance did not pose any risk to individuals.
"Police took this precaution to guarantee the safety of all concerned," said a PSNI spokesperson.
Earlier, a 30-year-old woman was charged with a number of offences connected to the murder - namely conspiracy to do an act with intent to pervert the course of justice, assisting offenders, and impeding police.
She was also further charged with possessing a class A controlled drug and possessing the same with intent to supply.
A 49-year-old man and a 61-year-old woman arrested by police investigating the murder have been released pending report.
A 40-year-old man remains in custody.