DES MOINES — A 3-foot giant rabbit that died last month following a United Airlines flight from London may have mistakenly been placed in a freezer by airline employees, a Des Moines attorney announced Monday.

Simon, a Continental Giant rabbit, was purchased by an Iowa-based ownership group with hopes that he could win the Iowa State Fair's biggest rabbit contest in August and be used to help raise money for the fair and its Blue Ribbon Foundation.

But the giant rabbit was found dead following a United flight from London to Chicago.

Related: World's-biggest-rabbit contender dies on United flight

Des Moines trial attorney Guy Cook announced at a press conference on Monday that the owners are demanding an independent investigation into Simon's death. At least one airline employee has reportedly said that Simon may have been inadvertently locked in a freezer for up to 16 hours after arriving in Chicago.


Additionally, the rabbit was cremated by United following its death, making an autopsy to determine what exactly happened impossible, Cook said. That action by the airline was tantamount to "destroying evidence" in the case, he said. The airline cremated the remains without the permission of the ownership group, he said.

"Whatever the cause of Simon's death may be, Simon died in the care of United Airlines' and its decision to destroy his remains establishes a reckless disregard for the Simon Group's rights and are indicative of the negligent care United Airlines provided Simon," a demand letter from the attorney reads.

In addition to the investigation, the ownership group is demanding the airline to pay for the purchase price of the rabbit, shipping costs and the "economic loss" of the rabbit's death. The demand letter gives United seven days to respond before a lawsuit is filed.

The giant bunny was purchased from British rabbit breeder Annette Edwards, who told the Sun newspaper that Simon had a check-up with a vet three hours before the flight and was “fit as a fiddle.” Edwards owns Simon’s four-foot long father, Darius, who currently holds the title as the world’s biggest rabbit.

“Something very strange has happened and I want to know what,” Edwards told the newspaper. “I’ve sent rabbits all around the world and nothing like this has happened before.”

The rabbit’s death added to the airlines’ headaches last month: United was widely criticized after video was made public of a 69-year-old passenger being dragged off a flight at Chicago O’Hare International to make room for a crew member.

PETA has criticized United, saying the rabbit's death "is not unique." It said "more than 300 animals have died in cargo holds since 2005, and many more have been been injured or lost."

The rabbit's three main owners were retired Wells Fargo executive Mark Oman, People's Co. president Steve Breure and Benning Financial partner Duke Reichardt.