The police scene tape has been removed from an access road near a slough situated near an Airdrie area acreage under police investigation.

Members of the CPS K9 unit, HAWCS (the Calgary Police Service helicopter) and a CPS boat were deployed to search a slough on a rural property situated approximately 500 metres north of the acreage. The search of the body of water ended shortly before 5:00 p.m.

Calgary police continue to search an acreage on Range Road 291 on the outskirts of the city of Airdrie.

A man who was transported by police from the acreage on Friday night has been released from custody but remains a person of interest in the ongoing investigation into the disappearance of a young child and his grandparents.

Neighbours confirm the 'person of interest' is Douglas Garland, a man who lives on the acreage which belongs to his parents.

A pickup truck was seized from the property but police have not confirmed if the vehicle, the person of interest, or the property are linked to the missing persons investigation.

An Amber Alert remains in place and police are asking for anyone with information about the whereabouts of five-year-old Nathan O’Brien or his grandparents, Kathryn and Alvin Liknes, to contact the CPS or Crime Stoppers.

The child and his grandparents were last seen on Sunday June 29 at the Liknes' home in the southwest Calgary community of Parkhill. Police have confirmed a violent incident occurred in the residence.

In a conversation with CTV, Rod O'Brien, Nathan's father, said the family had been informed by police that a person was being questioned but the O'Briens have not received an update on the investigation.

Rod says the family continues to pray for the safe return of Nathan, Kathy and Alvin.