Police are investigating the circumstances surrounding the sudden death of a baby in the Keady area earlier today (Tuesday).
Major Investigation Team detectives confirmed the investigation was underway.
A 31-year-old man has been arrested in the Craigavon area and has been taken to Banbridge Police Station where he is being questioned by detectives.
Forensic officers have been working diligently on a property in the Market Street area of the town throughout the evening.
A post mortem is due to take place to determine the cause of death.
Newry and Armagh Sinn Fein MLA Cathal Boylan said he had spoken to a family member of the baby.
He said: “They are all in deep shock. They have asked for privacy as they try to come to terms with this unfathomable tragedy.
“We shall of course keep them in our prayers.”