The pilot reported that the first flight of the day commenced at 0700 hours and landed to refuel after one hour and forty five minutes. She stated that before refuelling, she dipped the tank and noted that there was 15 to 20 litres of fuel remaining. The next flight commenced at 0900 hours, and at 1040 hours the helicopter departed the muster area to return to the refuelling point, which was about five minutes away. About two minutes later, the engine coughed once and then stopped. The aircraft was autorotated onto a cleared track, and during the landing the mainrotor struck the tailboom and the skids were bent. Inspection of the wreckage revealed that the fuel supply had been exhausted. This occurrence was not the subject of an on-site investigation and the above information was provided by the pilot and passenger.