The invention relates to a gypsum -fibre composite product, wherein the gypsum appears as crystals on the surface of the fibre and wherein the gypsum crystals are obtained by contacting calcium sulphate hemihydrate and/or calcium anhydrite and an aqueous fibre suspension. The invention also relates to a process for the preparation of the gypsum -fibre composite product. The composite product can be used as a filler pigment or coating pigment in the production of paper.
