A Garda forensic team is examining the scene of a fire at a Tipperary house which has been at the centre of a bitter dispute.
Extensive damage was caused to the property in the town of Ballina, north Tipperary, which has been controversially allocated to a Traveller family.
More than 60 nearby residents recently lost a High Court challenge against North Tipperary County Council to stop the letting from going ahead.
The house had been the subject of a blockade by local residents after it was learned the local authority had purchased it with a view to renting it to the O'Reilly family.
Gardaí said a number of fire crews were called to the scene shortly after 2am and brought the inferno under control.
Investigating officers said the house was unoccupied at the time.
"No-one was injured in the blaze," said a Garda spokesman. "The scene has been preserved for a technical examination to determine the cause."
The residents of Cullenagh in Ballina took judicial review proceedings against the county council to stop it from giving a tenancy agreement to the O'Reilly family, who had been on the housing list since 2000.
The court heard the couple and their eight children, one of whom suffered from a physical disability and three of whom had special needs, were living in cramped and unfit conditions.
In May, Mr Justice Michael Hanna found the council should grant the letting under the most stringent terms.
The residents are planning to appeal to the Supreme Court.
Local Fine Gael councillor, Dr Phyll Bugler, said people were awaiting the results of the forensic examination. "We do not really know yet what happened, if it was a electrical fault or how it was caused," she said.