Calgary Police have released a man they took into custody as they continue to search for five-year-old Nathan O’Brien and his grandparents.Police questioned 55-year-old Douglas Garland earlier and say, despite his release, he remains a person of interest. Reports also say Garland has a link to the Liknes family: his sister is in a common-law relationship with a member of the family.There are also reports he once operated an illegal drug lab on a property that’s now being searched by police. It’s a field and body of water near Airdrie, Alberta. Investigators were joined by a canine team and officers in a boat while a helicopter hovered overhead.The little boy and his grandparents, Alvin and Kathy Liknes, have now been missing a week. Police have confirmed a violent incident occurred in the home.