Amy the Continental Rabbit, who was nearly four feet long and weighed three stone, is understood to have died of a heart attack after travelling from its home in Worcester to Milan.
It was due to appear on the Italian version of Record Breakers, but the excitement proved too much and it died in a hotel room shortly before the television debut.
Last year, the giant rabbit usurped its mate Roberto's Guinness World Records crown as the world's biggest rabbit.
Having had more than 30 babies, Amy was so big it had to sleep in a dog kennel and cost £10 to feed a daily diet of two apples, a pile of carrots, half a cabbage, fresh hay and a dog bowl of rabbit mix.
Its owner Annette Edwards, 56, told the Sun of her pet's demise: "It is a mystery. She was healthy, not that old for a rabbit and the vet had deemed her fit to fly."
But Mrs Edwards is now hoping that Amy's offspring Alice will keep the largest rabbit title in the family. "We think Alice is two inches longer," she said.
A Guinness World Records spokesman said: "We are sad to hear of Amy's death."
http://www.telegraph.co.uk/health/petshealth/5276376/Worlds-largest-rabbit-dies-before-TV-appearance.html
