Abstract: A process and apparatus for washing high consistency fibre stock in the de-inking of paper. Grey stock is passed along a passage from a grey stock inlet to an outlet for cleaned stock. The passage is defined by a filter screen preferably of wire gauze. Within the passage is disposed a stirring member. Washing liquid such as water is introduced into the passage preferably by means of apertures in a central portion of the stirring member. Effluent liquid passes through the screen for extraction through a suitable outlet, or for recirculation. The arrangement is such that relative rotation of the screen and member results in clusters of stock fibres, which move around the passage as they pass therealong. The stirring member preferably includes a plurality of longitudinally extending, axis parallel bars radially spaced from the central portion.