The baby's body found in a Limerick suburb on Sunday was that of a full-term baby girl, who gardai believe had been dead for a number of days.
After a post-mortem examination was carried out by the assistant State pathologist, Dr Marie Cassidy, gardai said they were still trying to establish how the baby died.
Further tests are required and could take a few days. It was not possible to say conclusively at this stage if the baby was stillborn or had independent life after birth. It is understood, however, the baby did not die violently.
While playing on the Green at East Singland Road in Garryowen two young boys found the body of a new-born baby in a black plastic bag.
They were playing hurling after the Limerick-Wexford match. At the scene yesterday, bouquets of flowers were placed at a cordoned-off barrier and beside a Garda tent where the discovery was made.
The mother of one of the children who found the baby said her son came into the house and shouted: "Mammy, there's a dead baby in the bag."
She added: "I brought out a towel and placed it over the bag, as children were coming over. I thought it was a doll at first."
Supt Tony Kennelly, Henry Street, appealed to the mother of the child to come forward. "She will be treated with the greatest sympathy and sensitivity. The primary concern is for the mother."
She, her relatives or friends can contact the station at 061212400 or the confidential Garda line 1800 666111.