Garda investigations into the suspicious deaths of Michael Coleman and Liam Coffey in Kinsale, Co Cork, on Sunday, are continuing.
The three arrests came after gardaí received information about the deceased men’s final movements.
Gardaí also found evidence of “some drug abuse” in the cottage on Abbey Lane where the men’s bodies were found.
But they are still awaiting the results of toxicology tests before a drugs link in the deaths can be confirmed.
Waterford pair Michael Coleman of Ballinclamper, Dungarvan, and Liam Coffey of Cappoquin, both 22, were found dead by Mr Coleman’s girlfriend in the house the couple shared. Gardaí were alerted and sealed off the scene.
Superintendent Eddie MacEoin confirmed detectives found evidence of “some drug abuse” after the bodies were removed.
Acting on information, he said, detectives from Bandon and Kinsale arrested two men in their 20s in Cork City on Sunday night on suspicion of drug dealing.
They also arrested a woman in her 20s in Cork City yesterday afternoon — also on suspicion of drug dealing.
All three were detained under the provisions of Section 4 of the Criminal Justice Act, which allows for their detention for up to 24 hours. The two men were released without charge last evening.
The woman was also released without charge just before midnight.
Mr Coleman and his girlfriend moved to Kinsale recently after he secured a job at the Eli Lilly pharmaceutical plant in nearby Dunderrow. He started the job last week.
Mr Coffey had been visiting his friend for the weekend. It is understood Mr Coleman’s girlfriend went to bed at about 11pm on Saturday and left the two friends alone downstairs.
She found their bodies in the downstairs living area at around 6am on Sunday and raised the alarm.
Dr Margot Bolster, the assistant state pathologist conducted an autopsy on the remains at Cork University Hospital yesterday.
The preliminary results were presented to gardaí.
Flags flew at half mast at Cork Institute of Technology yesterday as a mark of respect for Mr Coleman, a first-class honours graduate in chemical engineering from CIT. His father, Kevin, is a CIT staff member.