A woman whose body was cut up and dispersed in mountains south of Dublin has been named locally as Patricia O'Connor.
A 32-year-old man is being questioned in connection with her death.
Ms O'Connor's remains, including her head and hands which were found in a bag, were discovered in eight places, Irish broadcaster RTÉ reported.
Gardaí (Irish police) are investigating whether the murder is linked to a personal dispute.
Detectives believe the victim, who was in her 50s and from Rathfarnham in southern Dublin, was killed in the city.
Gardaí also believe she was killed at a house in Rathfarnham at the end of May after being struck with a blunt instrument during a row.
She was reported missing on 2 June.
Detectives believe her remains were dismembered in a field outside Kilmuckridge in County Wexford, 130km (80 miles) south of Dublin, and buried in a shallow grave, RTÉ reported.
It is understood that while some body parts have been discovered in that field, detectives believe the killer came back two days later, disinterred and dismembered the rest of the body.
Gardaí believe the killer then drove back to Dublin through the Wicklow Mountains dispersing the victim's remains along 20km of the Military Road route, which crosses the mountains.
A 32-year-old man subsequently presented himself to police, was arrested and is being questioned at Bray Garda Station in County Wicklow, 12 miles south of Dublin, where he can be questioned for up to 24 hours.
Two new crime scenes were sealed off in Dublin and Wexford on Wednesday.
The search of the Wicklow mountains continued on Wednesday as more than 200 gardaí and Irish soldiers continued to look for evidence and human remains.
Eight locations remain sealed off there.
Garda Supt Pat Ward, described the unprecedented case as "troubling".
"We are conscious of the fact that the body found is that of a loved one," he said.
"What we have found are limbs, we've also found some significant parts of the torso and we've also found in one of the locations, in a bag, the head and the hands of the deceased."