Nathan O'Brien was reported missing Monday when his mother went to pick him up after a sleepover at the grandparents — Alvin and Kathy Liknes.
No one was home and an Amber Alert was issued by police.
Nathan's father, Rod, said the family would be offering a reward.
Chief Rick Hansen said in cases like this a reward can just cause more work for police because all kinds of people could step forward with bogus tips that must be checked out.
"If you do use a reward, if there is a lot of money that is created for a reward, frequently it increases the workload because you have got all kinds of people then who step forward with information that may not even be related to it," he said Wednesday.
"You have to at that point in time filter any and all information that you get and if you have a significant reward it does add to the workload, not only for us, but for the Crown prosecutors and everybody else."
Hansen said if people have information about a case they will usually call the Crime Stoppers phone tip line.
Calgary police were to told a media availability Wednesday afternoon with family members of the missing boy and his grandparents. (CHQR, The Canadian Press)