Three people have been arrested as part of the investigation into the disappearance and murder of William Maughan and Anastasija Varslavanne.
William and Anastasija were reported missing from Laytown, Co Meath in April 2015.
In September 2016, the case was reclassified as a murder investigation.
Two men, aged in their 50s and 60s, and one woman in her 40s are being detained at garda stations in Meath and Dublin.
Ongoing searches are being carried out in Co Meath this morning.
Gardaí are continuing to appeal to anyone with information relating to this investigation to contact them at Ashbourne Garda Station on 01 801 0600 or the Garda Confidential Line on 1800 666 111.