An emergency press conference was this afternoon held into the fatal fire which claimed at least three lives.
Detective Superintendent Jane Humphries said “This morning a fire broke out at a house in the Molly Road area of Derrylin which has tragically claimed the lives of at least three people.
"First and foremost our thoughts are with them and their relatives.
"At this time we believe the fire was started deliberately.
"A fully trained team of PSNI detectives are now investigating and are examining the scene along with our colleagues in the Northern Ireland Fire and Rescue Service.
"Investigations are at an early stage however, I can provide an update on what we know so far.
"Police were called to an address in the Molly Road area of Derrylin at around 7.20am this morning. We believe the fire began in the early hours of this morning.
"We are particularly keen to speak to anyone who was in, or travelling through Derrylin between midnight and the time the fire broke out.
"A 27 year old man has been arrested on suspicion of murder. He was detained at the scene and transferred to hospital for treatment prior to his arrest.
"Anyone with information should call 101, quoting reference number 179 27/02/18.”