The incident occurred on Thursday.
Three men in Co. Down have been arrested after the death of a 20 year old woman.
Police in Northern Ireland received a report that a woman had been found collapsed in her apartment building at around 8.30pm on Thursday.
She was found in a unit of flats on Dromore Street in Ballynahinch and it was later confirmed that the woman had died.
A post mortem is set to take place at a later date to determine the cause of death.
Despite no cause of death as of now, three men have since been arrested on suspicion of manslaughter and are currently in custody as police enquire about the death. Two men are aged 26 with the other aged 30.
A PSNI spokesperson said: “We would ask if anyone was in the wider Dromore Street area last night and noticed anything suspicious at this address or in the wider area to contact us on 101 quoting reference 1626 02/12/21.”
