Detectives investigating the disappearance and murder of Co Down man Pat McCormick have called in a specialist team to carry out underwater searches in the Castle Espie Wetlands.
Searches are due to get under way at the site on the shoreline of Strangford Lough this morning.
Mr McCormick, 55, was last seen walking towards flats on Castle Street in Comber on the night of Thursday, May 30.
Two people - a 26-year-old man and a 20-year-old woman - were arrested and questioned on suspicion of murdering the father-of-four.
Two men aged 20 and 39 were later detained by police on suspicion of perverting the course of justice and assisting offenders.
All four have since been released pending further inquiries.
Police have appealed for anyone with information about what happened to Mr McCormick to contact them on 101.