Abstract: | It is shown that ap-group with cyclic centre can be embedded in a finite group as a normal subgroup contained in its Frattini subgroup if and only if it is either an extraspecial 2-group of order at least 27 or the central product of a cyclic groupQ of order ≧4 and an extraspecial groupE of order ≧25, amalgamating Ω1 (Q) and the centre ofE. |