Aylesbury Police are renewing their appeal to find missing boy, Michael.
When he was last seen, he was wearing a dark coloured tracksuit, a green jacket, black trainers, a baseball cap, and was carrying a dog toy.
Michael has links to Sheffield, Leicester, Essex and London, but lives in Aylesbury.
They believe that Michael might poor health.
If you see Michael, call 999, quoting Thames Valley Police reference 43220382443.