On 27 September 1930, while in Egypt dealing with some problems which had arisen with this dam project, Sir John took a rowboat from the beach of the Casino Hotel near Alexandria, Egypt. Sometime later, the boat was found empty, and a search party was launched. They soon retrieved Sir John's body, floating in the water, with a bullet wound through the temple. No weapon was found, but the coroner's court gave a verdict of suicide. His body was brought back to England and he was buried at Mickleham, Surrey, on 18 October 1930 at the age of 59 years old.