The body found on the grounds of an unoccupied house in Salthill two days ago is now believed to be that of a young man in his twenties.
The State Pathologist, Dr John Harbison, carried out a four-hour post-mortem on the remains in University College Hospital, Galway, last night.
However, Dr Harbison was unable to establish if the deceased man had died of natural causes or whether foul play was involved.
Gardaí in Galway expect it could be some days before they identity the body. The skull and separated torso were discovered during work on the house, which is close to Angel's Lap Dancing club.
Earlier yesterday, Dr Harbison visited the locations where the remains were found.
The skull was found in the back garden of the house, and this led to a search through debris which had been removed during the work on the site. A torso was found, wrapped in a sleeping bag and tied with a blue nylon cord.