An undated photo obtained yesterday from Australia's Royal Society for the Prevention of Cruelty to Animals (RSPCA) shows a giant woolly sheep on the outskirts of Canberra.

Animal welfare officers put out an urgent appeal for shearers after finding the sheep with wool so overgrown its life was in danger.

The very woolly merino sheep was spotted wandering just outside the capital Canberra by bushwalkers, who alerted the RSPCA.

"It's definitely one of the biggest sheep we've ever seen," said the RSPCA's Ms Tammy Ven Dange yesterday. "He's pretty stressed out at the moment. We're trying to keep him calm and hopefully tomorrow we're going to sedate him and shear him."

Champion shearer Ian Elkins responded to the RSPCA's appeal and said removing the fleece "could be one of my biggest challenges yet". The process is expected to take between one and two hours.