Malnutrition may have caused the deaths of the three sisters found dead along with their elderly aunt at their home in Leixlip, Co Kildare, last week, it has been learned.
The sisters are understood to have become deeply concerned in the past two months when their aunt, Mrs Frances Mulrooney, who was 83, began to show signs of severe ill health.
Mrs Mulrooney had looked after the three sisters for more than a decade since the death of their mother in 1988.
The three sisters, whose family name was Feeney, changed their name by deed poll to Mulrooney, apparently because of their affinity with their aunt. Relations and neighbours said the sisters, Catherine and Ruth (51) and Josephine (46), referred to Mrs Mulrooney as "Mammy".
It is known that Mrs Mulrooney had been in failing health in recent months.
Gardai suspect the sisters may have given up eating in the weeks before their deaths. The four had been dead for some weeks before being discovered last week.
Despite earlier reports that the women might have been overcome by central heating fumes, this does not now appear to have been the cause of their deaths. An inspection of the central heating system in the house is understood to have shown that it had not malfunctioned and that this was not a likely primary cause of the deaths.
The sisters had barricaded the doors of the house, but there was no clear reason for this. They had, in the past, lived in parts of Dublin where they were subjected to break-ins. Relatives have said they were nervous about break-ins and had become increasingly reclusive in recent years.
The sisters were part of a family which ran a well-known hardware store in the Dolphins Barn area of Dublin until the 1980s. Before moving to Leixlip they had lived in a rented house in Sandymount and neighbours there also described them as eccentric.
The funerals of the sisters and their aunt took place at the weekend after a service at St Mary's Priory, Tallaght. An inquest will be held by the Kildare County Coroner.