On (2n, 2, 2n, n) relative difference sets

In this article, we show that a (2n, 2, 2n, n) relative difference set in a group G of order 4n exists only if a Sylow 2-subgroup of G is non-cyclic and n is even unless n = 1. we also construct (2n, 2, 2n, n) relative difference sets relative to non-normal subgroups.