The man was aged in his 30s and thought to be a non-national.
Preliminary reports suggest the man was stabbed up to 40 times.
His remains were discovered near Ballyboughal, in north Co Dublin at 10.40am yesterday.
It is understood the body had been along a laneway and in or near a ditch.
Gardaí believe there are other scenes that may need investigating as an initial examination indicated he was possibly killed elsewhere.
Superintendent Noel Carolan from Balbriggan Garda Station said investigating gardaí are unsure as to when the man’s body was left at the scene.
He said gardaí are appealing to anybody who was in the area yesterday morning or Thursday evening.
The superintendent said: “We’re not entirely sure how far back this man’s body actually came to the scene here.
“Anyone who was here over the last day or two who saw anything suspicious or unusual like vehicles or people in the area, get in contact with us at Balbriggan Garda station.”
There are no reports of missing people in the area in recent times.
“We’d like anyone who was his family, his work colleagues, would be in a position to come forward and let us know when they last saw him,” said Supt Carolan.
Gardaí say the man met a violent end. “We are satisfied it was violent and we are at a stage where we have commenced a murder investigation.
“We don’t have any reports of anyone missing in the area or locality. It looks as if he could have been there overnight or maybe even a couple of days before that.
“In all probability, we are probably looking at a situation where the fatal injuries did not take place here.
“It probably means there is more than just one scene.”
Gardaí are asking anyone with information to contact Balbriggan Garda Station on 01 8020510, the Garda Confidential Telephone Line, on 1800 666111, or any garda station.