By Michael McHugh and Rebecca Black, Press Association/ Q Radio news
Police have identified the man who was found dead alongside a mother and her teenage daughter in a Newry flat as Russel Steel.
The 38 year old was originally from Scotland.
All three bodies were discovered at the property in Glin Ree Court on Thursday morning.
A post-mortem examination found 15 year old Allison Marimon-Herrara was strangled to death.
Detectives say its 'highly likely' her 37 year old mother, Giselle, originally from Columbia, died in the same way.
Police said Mr. Steel, who also lived at the address, died by hanging.
Officers from the Police Service of Northern Ireland (PSNI) have launched a murder investigation and are not looking for anybody else.
Officers went to the flat close to the city centre after a relative reported concerns that they had not been in contact with a family member for days.
The bodies were discovered at about 11am on Thursday after police forced entry.
(Glin Ree Court, Newry)
Mr Murphy added: "This is an unspeakable tragedy."
Ms Marimon-Herrera is originally from Colombia and moved to Northern Ireland four years ago.
She worked in the Newry area.
Her daughter Allison was born in Spain and has lived in Northern Ireland since 2017.
She attended Newry High School.
Mr Murphy added: "I believe that Giselle and Allison were still alive in the early hours of Sunday morning but family members have not been able to contact them since."
According to the Irish Times, the victims' family have requested consular assistance to allow them to travel to Northern Ireland.
Fabian Marimon, reportedly the woman's father, said he was seeking help through diplomatic channels to visit Newry to find out what happened to his daughter.
Yadeli Marimon, the sister of the dead woman, told local media that the family had become worried after not hearing from the mother or daughter since the weekend.
(Mother and daughter Giselle Marimon-Herrera, 37, and Allison, 15)