Darius, a Continental Giant rabbit, disappeared from his enclosure in a backyard in the village of Stoulton over the weekend, the West Mercia Police force said.

They did not elaborate on why they thought it was a theft instead of an escape.

The force appealed for any information about or sightings of Darius, who is 129cm long at full stretch.

He holds the Guinness World Records citation for the world's longest rabbit.

Rabbits of his type are known to weigh between 7kg and 9kg.

Owner Annette Edwards, a large-rabbit breeder and model, urged the culprit or culprits to return Darius to his home 160km northwest of London, saying it was a "very sad day".

She initially offered a 1000 pound ($A1,800) reward but tweeted on Tuesday: "Please Please I am so upset Can you bring my Darius back I am putting the reward up to 2,000 pounds".

Australian Associated Press