Gardaí believe the man - whose body was discovered on the roadside in Wicklow this morning - died at the scene as a result of a gunshot wound.
The body was discovered by a passing motorist in a gateway near a wooded area at Annalecka Bridge, Ballinagee, on the main Hollywood to Glendalough Road shortly after 7.40am.
Gardaí said they were treating the case as a murder investigation but as yet had no particular leads.
The State Pathologist Dr Marie Cassidy has carried out a preliminary examinationat the scene and the body has now been removed for a full post mortem due to be concluded later tonight.
Superintendent Tom Mulligan, who is leading the investigation, said a thorough technical examination of the scene was being carried out.
"Like any investigation, we have to approach it with a wide open mind. The examination of the scene, which will re-commence tomorrow, should tell us something about how this person got there, when he got there or what condition he got there in," he said.
"I'd be quite happy to say that the result of the technical examination should yield very valuable information or results for us."
He said gardai had not yet identified the man. He appealed for anyone who was travelling recently on the road between Hollywood village and Glendalough to contact gardai.