A biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material having a sintered CAP core and a closed epitactically grown layer of nanocrystalline HAP deposited on the external surface of the sintered CAP core, wherein the closed epitactically grown layer of nanocrystalline HAP deposited on the external surface of the sintered CAP core has a homogeneous coarse external surface comprising flat crystal platelets, which shows an enhanced osteogenic response, a method of promoting bone formation, bone regeneration and/or bone repair by implanting the biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material, and a process of preparation thereof.