The invention relates to: &mdash；a porous biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material comprising a sintered CAP core and at least one uniform and closed epitactically grown layer of nanocrystalline HAP deposited on top of the sintered CAP core, whereby the epitactically grown nanocrystals have the same size and morphology as human bone mineral, i.e. a length of 30 to 46 nm and a width of 14 to 22 nm, which is impregnated with collagen fibers at a weight ratio of said collagen fibers to said porous biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material of at least 2%, &mdash；a process of preparing the above porous CAP/HAP bone substitute material, which comprises (a) mixing a slurry of collagen fibers and a porous biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material comprising a sintered CAP core and at least one uniform and closed epitactically grown layer of nanocrystalline HAP deposited on top of the sintered CAP core, whereby the epitactically grown nanocrystals have the same size and morphology as human bone mineral, i.e. a length of 30 to 46 nm and a width of 14 to 22 nm, and (b) eliminating the water by vacuum suction, &mdash；an implant which comprises a porous collagen matrix surrounding and impregnating particles or granules of porous biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material comprising a sintered CAP core and at least one uniform and closed epitactically grown layer of nanocrystalline HAP deposited on top of the sintered CAP core, whereby the epitactically grown nanocrystals have the same size and morphology as human bone mineral, i.e. a length of 30 to 46 nm and a width of 14 to 22 nm, &mdash；the use of the above bone substitute material as implant or prosthesis for bone formation, bone regeneration, bone repair and/or bone replacement at a defect site in a human or animal.
