The body of a man found in a house in south Dublin yesterday displayed signs of trauma.
However, gardaí are uncertain if the "bruising and injuries" that the man suffered are historical or may have happened more recently.
They are investigating the possibility that the man's house was broken into. It is understood his injuries were to his head and neck.
The case was being treated as a suspicious death last night, but sources said officers will not be able to establish if the man, believed to be aged 45, was a homicide victim until a post-mortem takes place tomorrow.
Yesterday gardaí made an appeal for information in the case.
"Gardaí are investigating the unexplained death of a man that occurred at a house in the Bluebell Avenue area," a spokesman said.
"Gardaí and Dublin Fire Brigade attended the scene following reports of a fire at the house at approximately 11.20am.
"The body of the man was discovered at the scene," the spokesman added.
"The body has now been removed for a post-mortem, the results of which will determine the course of the investigation."
The man's body was found in a bathroom on the property while the fire was in a separate area of the house in a bedroom.
"This man did have obvious injuries to his body - it's a case of finding out when and how they were caused," a source said.