"Two men were critically injured in a helicopter crash in an abandoned industrial park off Sixteenth Road in Midrand this afternoon," said Netcare 911 spokesman Jeffrey Wicks.

"Common-cause information suggests that the helicopter crashed and the wreckage disintegrated, the largest segment coming to rest against concrete palisade fencing. Netcare 911 paramedics arrived at the scene to find two occupants in a critical condition and they immediately initiated treatment," Wicks said.

One man was airlifted by helicopter to Sunninghill Hospital. The other was taken there by ambulance, he said.

The crash was at the junction of Sixteenth Road and Second Avenue, near the N1 highway.

"The cause of the accident and events leading up to it . will form the subject of a Civil Aviation Authority Investigation," Wicks said.