Lucky was raised by the Westgarths in a farming town in south-east Australia

The world's oldest sheep has died in Australia at the age of 23 - twice the normal life expectancy - after succumbing to a record heatwave.

Lucky hit the Guinness record in 2007 and was a celebrity in her hometown of Lake Bolac, near Melbourne.

The ewe had died on Monday at the farm where she had been found as a little lamb, her owner Delrae Westgarth said.

Lucky was hand-reared from birth after being abandoned by her mother. She went on to have 35 offspring of her own.

"She used to come and howl at the back gate, torment the dogs and that sort of thing," Mrs Westgarth told public broadcaster ABC.

Lucky, a Polwarth-Dorchester cross, succumbed to a weeklong heatwave, as temperatures soared above 30C (86F).

"We brought her into the shed where she was reared and put air conditioners on her," Mrs Westgarth said, but she did not survive.

Lucky - who became toothless and arthritic in her old age - had been buried under her favourite nectarine tree, Mrs Westgarth added.

A copy of her Guinness World Record certificate is on the wall of Lake Bolac's tourist information centre, which carries Lucky postcards, bookmarks and wool samples for sale, the Melbourne Herald-Sun reports.