Object collision

Ok so i need help with objects colliding into walls and floors when i pick them up
im creating a fps puzzle game but and i have it set up so that when the mouse is over and left clicked it picks the object up and that works but the problem is i can look down while holding the object and i can drop it right threw the floor or move it to the left threw the wall stuff like that when i pick the objects up they seam to loose there rigid body dynamics but when there not picked up they collide with the walls and floor just fine. can anyone help me with this problem? thanks.