An unidentified aircraft was heard to depart Kalgoorlie at approximately 0430 hours, and VH-UQR was subsequently reported to have been stolen. Some four hours later the aircraft was sighted, flying at low level, by a number of witnesses in the Margaret River area. The engines were reported to be not operating normally. The aicraft then disappeared from sight behind trees and was heard to crash. The wreckage was located in a heavily wooded area. An inspection of the site indicated that the aircraft had collided with the ground following a high speed descent at an angle in excess of 30 degrees. Neither engine was producing power at the time of impact. The investigation indicated that the fuel supply had been exhausted at the time of the accident. Although the aircraft was almost totally destroyed there was no evidence that aircraft components or systems contributed to the accident. Neither pilot was qualified to fly, or had any known flying experience, on the Cessna 310 or any other multi-engine aircraft type. The factors leading to the theft of the aircraft were not established.