The last confirmed sighting of Kyran was in June 2022 and he is believed to have been killed at some point in those two years. 

A number of properties had been searched by gardaí since the launch of the investigation, but no trace of Kyran was found. 

In an update on Monday morning, gardaí said a woman in her 50s is currently being detained under Section 4 of the Criminal Justice Act 1984, at a Garda Station in the Eastern Region.

A home in Drogheda, Co Louth, is currently being searched by gardaí. 

"Investigations are ongoing," a garda spokesperson said. 

At the time he was reported missing, Kyran had not been seen since May 2022, when he had been a pupil at a primary school in Dundalk.

In December 2024, gardaí said that images of Kyran, taken in June 2022, had been provided to the investigation team.

Also that month, 36-year-old Anthony Maguire was found dead at his home in Drogheda. He had been arrested in connection with the case previously before subsequently being released without charge.

The woman is the third person to be arrested as part of the investigation.

Three other properties have been searched previously.

Speaking to reporters on Monday, justice minister Jim O’Callaghan said he was pleased there has been a development in relation to “this horrific crime”.

He said while he would not comment in relation to the ongoing garda investigation: “Obviously there are people out there who have information in respect of this crime, and that information should be brought to the attention of An Garda Síochána.

“The only mechanism in order that justice can be served in Ireland is if the gardaí investigate, have sufficient information to pass on to the DPP for a prosecution, and then our courts deal with the matter.

“So, anyone who has information in respect of Kyran Durnin needs to give that information to An Garda Síochána.”