The pilot reported that when he selected the landing gear up, after departure, he heard a loud clunking noise. The mechanical landing gear indicator showed that the nose gear was not retracted. He also noticed a reduction in airspeed, and a wind noise from the front of the aircraft. The pilot advised Flight Service of the problem and continued to Bankstown where he extended the landing gear. However, inspection by engineers from the ground revealed that the nose gear was not fully extended. Airport emergency procedures were implemented. The aircraft was landed on the mainwheels, but the nose gear collapsed as it contacted the runway. An inspection of the aircraft subsequently revealed that an eye-end fitting, at the actuator end of the nose landing gear push-pull rod, had failed. The operator later reported that post accident landing gear rigging checks were normal, and the landing gear had operated normally after installing a replacement eye-end fitting. The reason for the failure was not determined.