The man, believed to be a native of Poland, died at Naas General Hospital yesterday after he was found with serious injuries at around 10:30am on Wednesday.
A post mortem examination is expected to take place today on the man's body.
The scene of the incident, about a kilometre outside Newbridge town, remains sealed off.
A man in his 30s who was previously arrested, has been released without charge and a file is being prepared for the DPP.
An incident room has been set up at Newbridge Garda Station.
Gardaí are asking any witnesses who can help with the investigation to contact them, and it's understood a number of people are helping them with their enquiries.
