By September 1945 Eastick had been appointed commander of Kuching Force, a detachment of the 9th Division which supervised the Japanese surrender in the territory of Sarawak, on the island of Borneo. Eastick oversaw the liberation and repatriation of Allied prisoners of war and internees in Sarawak, including the large Batu Lintang camp. He was military governor of Sarawak from 10 September 1945 until December 1945, when the territory returned to civilian rule. Eastick was subsequently made a Companion of the Order of the Star of Sarawak by the last White Rajah of Sarawak, Charles Vyner Brooke.