Police have confirm that the man found dead at a house in Banbridge on Monday was Richard Gerard Scullion.
The 55-year-old was found at a house in the Millmount Court area of the town.
Detective Chief Inspector Eamonn Corrigan said: “We are treating the death of Mr Scullion as murder and we are continuing to question a 28-year-old man who was arrested on Monday night.
“Earlier today we applied for and were granted an extension in relation to the suspect’s detention.
“I am renewing my appeal for witnesses or anyone with information to get in touch with us. Investigators can be contacted by calling 101, quoting reference number 1000 09/07/18.
“Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”
Sinn Féin MLA John O’Dowd said: “First and foremost, I want to send my sympathies to the man’s family and friends.
“Our thoughts and prayers are with them as they deal with the tragic and sudden loss of a loved one.
“Anyone with information about the circumstances surrounding the death should bring it to the PSNI immediately.”