A rabbit whose food bill tops a staggering £50 a week is in the running for the title of biggest bunny in the world.

At first glance Benny, a giant Flemish buck, could be a contender for the heaviest, as he tips the scales at 22.4lbs.

However, the Guinness World Records no longer records animal weights because of problems with owners over-feeding them.

But the two-year-old giant, whose owners Martin and Sharon Heather claimed measures 85cm in length, is now in the running to be crowned the longest rabbit in the world.

Previous record holder Amy, a continental giant doe who died in May, measured a paltry 81.5cm.

Mr and Mrs Heather have set up a Facebook site for Benny and are using his new-found fame to help save the Oxfordshire Animal Sanctuary, which is under threat due to a funding crisis.

The couple, of Merton Close, Eynsham, have picked up three of their four bunnies from the sanctuary in Stadhampton and want Benny’s fame — he already has 270 friends on his Facebook site bennyheather — to spread the word about the centre’s plight.

Mr and Mrs Heather are awaiting a vet’s appointment where Benny — who munches through £9-worth of fruit, vegetables, rabbit food, biscuits and treats a day — will be officially measured in front of independent witnesses, before their application goes in.

Guinness World Records spokesman Amarilis Espinoza said: “The longest rabbit is currently under research as we have had a couple of contenders.”

Mr and Mrs Heather, who have three children, came across the giant bunny at the sanctuary in February and Mr Heather brought him home as his birthday present.

Since then the couple have adopted two other rabbits from the sanctuary — April, a giant lop, and Flossy, a lop-eared rabbit.

Mrs Heather, 39, said: “On July 3, I really started pushing Benny’s Facebook site to try to get more people aware about the sanctuary.

“All the rabbits that have come from the home are a credit to the staff there as they are all so well-tempered, it’s unbelievable.”

Benny, whose ears alone measure 20cms, is house trained and likes to sit with the family dog Archie, a cross breed.

Mr Heather, 52, said: “We leave the back door open for him — he doesn’t try to escape, he is happy as pie.

“He also gives kisses and says what he wants. If he wants treats, he will jump up on the sofa. He lies with the dog and kisses the dog sometimes.”

Benny enjoys eating broccoli, but his favourite treats are fig rolls.

Mrs Heather said: “It is a real pleasure getting up in the mornings, finding the dog on one end of the settee and the rabbit on the other side of the settee.

“I am sure he is just a little bit confused about whether he is a dog or a rabbit, but he is definitely the business.”