A man (30) is still being questioned by gardaí in connection with an attack in Co Tipperary in which a woman (20) died and her brother (23) was seriously injured.
A postmortem was carried out this afternoon on the body of Joanne Mangan, who lived in a rented house in the remote Ballymuddagh area near Grange, about seven miles from Clonmel.
It is understood that Ms Mangan and her brother Eddie, who is in a critical condition in hospital, sustained stab wounds.
Gardaí said a man, who is believed to be from Clonmel, was being questioned over the killing and the second attack. He is being detained at Cahir Garda station and can be held until tomorrow afternoon.
The house was sealed off to allow forensic teams to carry out a technical examination. A kitchen knife was found in a garden behind the house today.
An ambulance was called after the discovery of the victims at around 12.30am. Ms Mangan was taken to South Tipperary General Hospital in Clonmel where she was pronounced dead.
Her body was later moved to Limerick Regional for a postmortem to be carried out by Deputy State Pathologist Dr Michael Curtis.
Mr Mangan was brought to Cork University Hospital where he is being treated for wounds to his head and body.
Mattie McGrath, Fianna Fáil TD for Tipperary South, who knows the Mangan family, said: "This is an awful tragedy to have visited upon them. It is very traumatic. The community are rallying round as best they can to support the family and do whatever they can to offer them help."
Additional reporting PA