A man has been arrested on suspicion of murder as part of the investigation into the disappearance of schoolboy Kyran Durnin.
Meanwhile, gardaí said they have completed the search of one property in Drogheda, while the search of a second house continues.
This search is being carried out by the Divisional Search team, supported by the Garda National Technical Bureau, Divisional Scene of Crime and Forensic Science Ireland.
A specialist cadaver dog is also on site.
The man arrested earlier is being held at a garda station in the east of the country.
Gardaí said the purpose of the searches in Drogheda is to discover any evidence which might provide them with information as to Kyran’s current whereabouts or what has happened to him.
Kyran, who would now be eight years old, was reported missing in August of this year, but gardaí suspect he may have been killed up to two years ago.
A woman who was arrested earlier this week as part of the investigation was later released without charge.
The woman, aged in her 20s, had been abroad for a period of time but was arrested in Ireland on Monday on suspicion of murder.
It is understood that she was known to Kyran and has been a person of interest in the case for some time, and that gardaí have also spoken to her on a number of previous occasions.
In August, a missing person’s report was filed at Drogheda Garda Station in relation to Kyran and gardaí were told he was last seen in the town two days beforehand.
However, during the course of this inquiry, information came to light that led detectives to suspect that Kyran had been missing for longer than two days.
In October, the missing person’s case was upgraded to murder.
Gardaí established that Kyran had previously lived at a house in Dundalk for a number of years and searched it and an adjoining area of open land as part of their murder investigation.
Gardaí have said the current tenants who live at the property are in no way connected to Kyran or his disappearance.
The results of the three-day search were not released for operational purposes.
The Child and Family Agency Tusla said that in August, it alerted gardaí to a significant concern about Kyran and that while he was not in its care, it had engaged with him and his family.
Tusla subsequently conducted an internal review into its interactions with Kyran and his family.
Gardaí are continuing to appeal to anyone with any information on the disappearance and murder of Kyran, no matter how insignificant it may seem, to contact the Garda Investigation Team at Drogheda Garda Station on 041 987 4200, the Garda Confidential Line on 1800 666 111 or speak with any member of An Garda Síochána.