Abstract: Enclosures nos. 3-4 to dispatch no. 21 from the Secret Department, Bombay Castle, dated 21 June 1861. The enclosures are dated April 1861. Received 15 [?] July 1861.The enclosures consist of letters from Lieutenant-Colonel Christopher Palmer Rigby, HM Consul and British Agent, Zanzibar, concerning the involvement of 'piratical Arab tribes' in the slave trade at Zanzibar. The second letter includes translations into English of Arabic letters found on the dhows involved.Physical description: 1 item (6 folios)