Gardaí have yet to formally identify the man murdered at the Mardyke in the early hours of this morning.
At a press briefing at the scene of the incident this afternoon, Superintendent Michael Comyns said the post mortem showed the man had injuries consistent with an assault and they treating the investigation as a homicide.
Mardyke Walk has seen a number of tents erected by homeless people sleeping in the area in recent months.
Gardaí were called last night at 12.45am by people in the area reporting that a tent was on fire and that a man was unconscious.
The injured man was removed to the Cork University Hospital where he died a short time later.
Superintendent Comyns said an incident room was set up and they appointed a family liaison officer.
He said they would not be releasing details of the post mortem for operational reasons but did say the man's injuries were consistent with an assault but he did not have injuries consistent with being in a fire.
At the briefing, he made an appeal for any witnesses who were in the area or may have heard something suspicious between 11pm and 1am to make contact with investigators.
"This area at night. There are a lot of people on foot and traffic in the area," he said.
He also said the area is surrounded by a number of guesthouses and any visitors to Cork who may have heard something suspicious are asked to contact the gardaí.
"We do believe there was some shouting during the evening and maybe not at the particular time of the incident," he said.
Any persons who were in Mardyke Walk area between 11pm and 1am this morning and who may have witnessed any activity in the area or any motorists who may have passed through Mardyle Walk around these times and have Dashcam footage to contact Anglesea Garda Station on 021 -4522000, The Garda Confidential Line 1800 666 111 or any Garda Station.