Our Private Detective Agency in Ghaziabad. Private Detective Agency offers detective or all investigation services in both personal and corporate cases in Ghaziabad. If you require a Personal Investigator in Ghaziabad then let us support you. The Private Detective Agency In Ghaziabad directed Mr. Hemant Aggarwal. He is the first Private Detective Agency in Delhi and a private detective agency in Ghaziabad, which is running a detective agency. At the initial stage of his career he was working as a detective after that he started his own detective agency by the name of “HR Investigation”.