The pilot stated that on touchdown, the left main wheel locked up, and the airplane pulled sharply towards the left. He stated that just before the airplane departed the left side of the runway, the left wheel must have "broke loose," and the airplane veered sharply to the right. The airplane's left wingtip and propeller struck the runway. According to an A&P mechanic, when the airplane was rolled into the maintenance shop, the "wheels rolled fine." Examination of the brake system revealed no problems noted. Examination of the left main tire found no flat spots.