The pilot had been carrying out a low-level survey of cotton fields en-route to Moree. At the completion of the survey as the aircraft was climbing through a height of 700 feet the engine suffered a sudden and complete loss of power. All attempts to restart the engine were unsuccessful and the pilot elected to force land the aircraft on a local strip. During the approach he realised the aircraft would not be able to clear trees on the approach path. He then turned the aircraft through about 60 degrees to the left and landed in a clearing. During the landing roll the left mainwheel struck a log resulting in substantial damage to the aircraft. The pilot advised that prior to the flight he had visually assessed the fuel contents as sufficient. Due to the position of the aircraft after the accident it was not possible to determine the amount of fuel remaining. A subsequent examination of the aircraft was unable to determine the reason for the loss of power.