A two-month-old baby boy is in a critical condition in hospital after suffering injuries consistent with 'shaken baby syndrome', the Sunday Tribune understands.

The baby is in Temple Street Children's hospital and is suffering from bleeding to the brain and retina of one eye. Doctors fear that the youngster will not recover and if he does he will suffer from permanent brain damage.

The infant's 24-year-old mother rushed her son to the Accident and Emergency department at Temple Street on Thursday after noticing that he appeared unwell.

Two days earlier she saw bruising on the infant's left cheek and when his condition deteriorated she brought him to hospital.

When doctors examined the baby they determined that the extent of the injuries meant that they had occurred non-accidentally and were consistent with an assault.

The Health Service Executive was immediately called-in and they contacted gardaí.

Detectives from Store Street garda station have launched a major investigation and have interviewed both the baby's parents, who have lived in Dublin's north inner city for several years.

The child's father has denied assaulting the child and says he has no knowledge about how his son sustained the injuries.

Senior garda sources say there is little doubt that the baby was assaulted but say there were no witnesses to anything that might have occurred. All friends and associates of the couple are being interviewed to see if they can shed any light on what occurred.

It is likely that a file will be sent to the DPP who will then determine if any charges should be brought.

Shaken baby syndrome occurs when children, usually under two, are violently shaken.

This results in swelling of the brain and internal bleeding which often leads to severe permanent brain damage. Symptoms include lethargy, breathing problems and convulsions.

Cases in Ireland are extremely rare.