AC3 Collison detection inside a movie clip (rather than with its bounding box)

I want to navigate a maze and therefore I want to create collison detection with the maze itself, but when I try the collison is made with the entire maze movieclip, so even if my character is safe in a corridor without touching the walls of the maze it still counts as collisons.

Is there a way to detect collison with the content iside the movieclip rather than it's bounding box?