A 30-year-old man is still being held on suspicion of murder after a mans death in Downpatrick, that police said might be linked to a "brutal" attack on a priest in a church in the town.
Officers went to a house in Marian Park at about 12:00 BST on Sunday after a report that a body had been found.
Police suspect the case might be connected to an attack on a priest, Fr John Murray, in St Patricks Church in the County Down town.
He was hit on the head with a bottle while preparing to celebrate his last Mass before his retirement. Police said he remained in a serious condition in the Royal Victoria Hospital in Belfast.
Police said a man walked into the church on St Patricks Avenue at 10:10 BST on Sunday and hit the priest before leaving.
Det Ch Insp McBurney said it "was a completely shocking and brutal attack and has left the priest with a serious head injury".
Fr Eddie McGee is a priest from the Diocese of Down and Connor and knows Fr Murray well.
He told BBC Radio Ulsters Good Morning Ulster programme that the man asked Fr Murray if he would hear his confession just before the morning service was due to start and "it was at that stage that he was attacked".
He said the parishioners who witnessed the attack then called the emergency services, describing it as an "absolute shock" for those who saw the "terrible event".
Fr McGee said Bishop of Down and Connor, Alan McGuckian, went to the hospital on Sunday night to meet with the family of Fr Murray and some of the clergy went to see the family of the man who has been killed.
He also sent his thoughts and prayers to the man who was killed and said that a "loss of life in such brutal circumstances is just very difficult to comprehend".
Fr McGee described Fr Murray as "very well known" and "very well respected priest" of the diocese who had been appointed a canon by the bishop in recognition for his work as a senior adviser.
He said a sign of his "commitment and dedication" to the community is that even in his retirement he planned to assist the local area.
Hundreds of people attended a vigil in Downpatricks St Brigids Church on Sunday evening.
Fr Martin Graham, who took the service, said it was about being with the parishioners and praying with them, for Fr Murray and also "for the other poor man who lost his life".
He said Fr Murray had given the last 11 years of life to the parish and was due to retire on Thursday.
"He is so well thought of by the people here," he said. "It is just heartbreaking for them in what was supposed to be a poignant farewell this morning that it turned into something which was just grotesque."
Supt Norman Haslett said enquiries were at an early stage and at this time, they suspect the Marian Park incident "may be connected to a serious assault in the St Patricks Avenue area of Downpatrick on Sunday".
Speaking about the death in Marian Park, SDLP councillor Conor Galbraith said a family were now in mourning.
"It is really sad that this has resulted in two daughters left behind, grandchildren left behind," he added.
"And for what, we just dont know why."