He was appointed chief of the army's intelligence section ("Deuxième Bureau, service de renseignement militaire") in 1895. The following year Picquart discovered that the memorandum (""bordereau"") used to convict Captain Alfred Dreyfus, had actually been the work of Major Ferdinand Walsin Esterhazy. Several high-ranking generals warned Picquart to conceal his discovery, but Picquart continued his investigation. In this he was hindered and sabotaged by subordinate officers, notably Major Hubert-Joseph Henry. As a consequence, Picquart was relieved of duty with the "Deuxième Bureau" and sent in December 1896 to regimental duty, commanding the 4th Tunisian Tirailleurs Regiment (native infantry) based at Sousse in French Tunisia.