Knocking noise when spinning, Candy Activa 105AC?

There seems to be something loose between the inner and outer drum. If I shake the outer drum I can hear and feel something loose banging against the side of the outer drum. The machine makes no noise when washing but when spinning a knocking noise can be heard. If I remove the top, and shake the concrete block, if I put my hand down the side of the drum I can feel something hitting the inner side of the outer drum.
Have I got a problem?