He was speaking at Drogheda Coroners Court yesterday where it was heard the newborn had died from blunt trauma to his head.
The State Pathologist Dr Marie Cassidy concluded death was due to head injuries caused by blunt trauma to the head.
Dr Cassidy carried out a postmortem on Johnny McCarthy, who had lived at Academy Square, Navan, on January 8, last year.
The inquest had previously been adjourned to allow his parents to travel from Britain, where they now live, to attend.
Yesterday, Detective Garda Inspector Gus Keane, Balbriggan, who is in charge of the garda investigation, told the court he had been in touch with police in Birmingham, who had spoken to the parents.
Registered letters were sent to both parents informing them of the inquest. Their solicitors were also told but the garda said the response via the British police was that they were not coming for the inquest.
However, the inspector asked for the inquest to be adjourned, saying they may return at a later date. He told the coroner the investigation is “current” and continuing.
The infant was pronounced dead at 6.05am on January 8 last year at Our Lady of Lourdes Hospital, Drogheda — where he had been born on December 29, some 10 days earlier.
He had been brought there from a house in Lusk a few hours earlier.
The death was treated as murder and a full investigation was carried out by gardaí from Balbriggan.
As part of the investigation, eight people were arrested, some on suspicion of withholding information.
Gardaí sent a file to the Director of Public Prosecutions, who decided not to instigate a prosecution.
Yesterday, Mr Maguire said he had sufficient evidence to be able to issue a death certificate for the baby and expressed his sympathies “to all those bereaved and who suffered the loss [of the infant]”.
“I would urge anybody who can assist gardaí in their investigation to do so,” he concluded.
The inquest was then adjourned, for the fourth time, to a date to be set later this year.