Difference Sets Disjoint from a Subgroup II: Groups of Order $$4p^2$$

We study finite groups G having a normal subgroup H and \(D \subset \setminus H, D \cap D^{-1}=\emptyset ,\) such that the multiset \(\{ xy^{-1}:x,y \in D\}\) has every non-identity element occur same number of times (such is called DRAD difference set). show there are no order \(4p^2\), where p an odd prime.