A THREE-month-old boy was fighting for his life last night and his twin brother remained stable in hospital as gardai investigated how both sustained serious head and chest injuries.
Gardai stressed that the nature of their investigation would be determined by a medical report on the possible causes of the infants' injuries.
One of the twins is now struggling to stay alive in Dublin's Temple Street Children's Hospital after being transferred from Cork where the baby brothers were first brought for medical treatment.
The twin boys were taken separately to Cork University Hospital (CUH) on January 9 where they were initially treated in the emergency department.
One of the babies was in such a serious condition he was immediately transferred for specialist paediatric care to Temple Street. The boy was diagnosed with a series of serious bleeds on his brain.
Surgeons have attempted to deal with the haemorrhage and the little boy has been battling to recover for the past eight days.
He was in a critical condition yesterday and remained on a ventilator. The next 48 to 72 hours are said to be critical.
The boy also had injuries to his torso and doctors are trying to confirm if he has broken ribs.
The other child's condition is less serious and the boy remains under the care of doctors in CUH for head and torso injuries.
Gardai were notified of the matter by healthcare staff, in accordance with HSE guidelines.
Detectives are now liaising with doctors over the incident and how the two infants sustained such serious injuries.
One garda source stressed that the nature of their inquiry would only be determined once the medical reports on the specific injuries involved were received from CUH.
"The reports will be central to everything," he said.
The reports are being compiled by the doctors directly involved in treating the twins and by paediatric and emergency department specialists.
It was unclear last night whether the boys had been involved in any type of accident before January 9.
The parents of the twins are a 19-year-old woman and a 20-year-old man. They have been together for the past two years.
Both live in Co Cork and are not understood to have any other children.
The father is from a very large extended family in the Cork area.
Gardai are now liaising with them over the matter.
However, a formal statement has not yet been taken from the couple by gardai about the precise circumstances in which the two infant boys sustained their injuries.