The Supreme Court has reserved its decision on whether or not it should hear an appeal relating to the rights of parents and children and the duties of the Health Service Executive in applications to take children into emergency care.
Lawyers on behalf of a baby who was removed from his mother at one day old are appealing a High Court decision that his removal was valid and lawful.
The child is now back with his parents after an emergency care order granted by a district court expired.
The district court refused to grant a longer term care order and imposed a supervisory order instead.
The HSE is arguing that there is no point in this Supreme Court appeal going ahead as the child is now back with his parents.
Lawyers for the child, who is taking the action through his mother, and lawyers for his father, say the case raises issues of exceptional public importance, which could affect all childcare cases and should be decided by the Supreme Court.
Senior counsel for the child, Michael O'Higgins, said the effect of the High Court's ruling was that parents whose child was taken from them under an emergency care order would not have an opportunity to make their case until the second stage of proceedings, after the first emergency care order expires.
He also said where there were serious allegations against one parent, the district court is obliged to consider if the child can be left in the care of the "innocent" parent.
He said the High Court was wrong to rule that this did not have to be done in every case.
Five Supreme Court judges heard arguments this morning.
They will decide at a later date whether they should go on to hear the appeal in full or whether the issue is effectively "moot".