The owners of the derelict property where schoolgirl Ana Kriegel was murdered were told by a local authority the site was being trespassed on and might end up being used by rough sleepers.
Fingal County Council (FCC) raised a series of issues with security at the site at Glenwood House in Lucan, Co Dublin, saying it was concerned it would be used in the run-up to Halloween to find material for bonfires.
In correspondence with the owners' representatives last month, the council said it had carried out an inspection of the site and discovered a surrounding fence had been damaged.
"The site can now be accessed by pulling this fence aside," said one email.
"There appeared to be signs of trespass also within the site."
The council said this area needed to be secured "as soon as practicable" and that a close watch should be kept on the site in the run-up to Halloween.
It also warned there were other easy access points to the site, including one through a back entrance to the farmyard.
"It is easy to walk up the bank and around the fence to gain entrance to the site," an email said. "This needs to be secured."
A hole in a wall on the property also needed to be secured, according to officials, as it provided "easy access" to the site.
Two outhouses on the property were a cause for concern too.
"Consideration should be made to close up the doorways to these outhouses as they could provide a shelter for people sleeping rough," the email said.
The council also said that if there was any evidence people were sleeping on the site, homeless services would have to be alerted.
Two other possible access points were also flagged, including a rotten window that could easily be pushed through and a fence at the front of house, which might need to be raised.
Glenwood House was the scene of one of Ireland's most notorious murders of recent years, when 14-year-old Ana was killed there in May 2018.