Date: It was on HBO, in 1997-1998.
Plot: The younger brother of the protagonist disappears and he organizes a search party from 3 of his friends to look for him. I think they are all boys (teenagers probably). The protagonist is a short, stocky boy with dark, curly hair. Another guy has short, blond hair, he never says anything and he's filming everything they do with a camera. In the end, it's revealed that the missing brother was in the cellar of their own house from the beginning.