Gardaí in Galway are now investigating the possibility that the man whose body was found in a freezer at the rear of a fish shop in the city last week may have been murdered up to four years ago.
They are also trying to establish if his body has been in the cold room since 2003 - or if it was put there at a later date.
Gardaí have named the dead man as 52-year-old Patrick McCormack from Upper Artane Cottages on the Malahide Road in Artane.
He was suspected of being a drug dealer.
Mr McCormack was last seen alive in October 2003 and was reported missing at the time.
Superintendent Tom Curley, who is heading the investigation, says the gardaí are particularly anxious to hear from anyone who may have seen Patrick McCormack since that date or who may have seen a car he had at the time.
The car was a green Opel Record, registration number 97 D 9981; it was recovered in the Co Clare area.
Supt Curley also said there was a possibility that the dead man had been killed in 2003 or 2004 and that his body may have been in the cold room since then.
Mr Curley said it was not possible to rule this in or out at this stage.
He also confirmed that a post mortem examination which was due to take place in Dublin today has been deferred because of the condition the body remains in.
Deputy State Pathologist Dr Michael Curtis carried out a preliminary examination at the scene last Wednesday. It is hoped that a full post mortem will take place later this week.
A murder investigation was launched last week after the body was found. A team of up to 50 uniformed gardaí and detectives are now involved in the investigation.
The cold store where the body was found remains sealed off and it is not yet known if the man was killed there or if he was killed at some other location and taken there.
