The 44-year-old man became trapped two miles underground when the tractor he was driving hit a bump in the road and fell on him.

Another worker found the man and called for help, but before it arrived the miner used a knife to cut though his arm just below the elbow.

The miner was flown to hospital after escaping, but doctors were unable to re-attach his arm according to a mineworker's union spokesman.

The man's name hasn't been revealed, and Australian police are investigating the incident to try and work out exactly what happened.