United Airlines hasn't explained why a giant rabbit died after being flown from London to Chicago or why it had the animal cremated within hours of his death, a lawyer for the rabbit's buyers said Monday, announcing possible legal action.

Des Moines Attorney Guy Cook, representing an Iowa group that bought the continental giant rabbit named Simon, said his clients want details about Simon's death and an explanation of why he was cremated before a necropsy, or post-mortem examination, could be conducted.

Cook said he sent a letter to United on May 4 but hasn't received a reply, other than a confirmation that the matter had been referred to the airline's lawyers.

"United has taken no action to rectify this," Cook said, raising larger questions about how the airline treats the animals it transports. "This case is about more than one rabbit."

Simon flew from London's Heathrow Airport to Chicago on April 20 and was supposed to fly an onward leg to Kansas City, Missouri, but he died after landing at O'Hare International Airport.

United spokesman Charles Hobart said the company had reached "a satisfactory resolution" with the rabbit's breeder, Annette Edwards, in Worcestershire in the United Kingdom. Asked about the letter from the animal's buyers, the cremation or other issues, he said only that Edwards was United's customer and that she had turned down an offer of a post-mortem examination. He declined to answer other questions.

News of the rabbit's death came as the airline was struggling to repair its image following the videotaped removal of a passenger from a United plane at Chicago's O'Hare airport. Images of the passenger, who was battered as he was dragged from the plane, circulated widely on social media and prompted condemnation and threats of a lawsuit. The passenger quickly reached a settlement with United for an undisclosed sum.

Earlier, the airline was criticized after two young girls weren't allowed on a flight because they wore leggings.

Speaking in front of a large video monitor displaying a photo of the dead rabbit on its side in a large crate, Cook said the group of Des Moines area businessmen who bought Simon had intended to display him at this summer's Iowa State fair. After winning a prize for the largest rabbit, the men intended to take Simon to other events and raise money for the fair, an iconic Iowa event that stretches over 11 days in August, Cook said.

The owners are seeking the costs of buying and transporting the rabbit — estimated at $2,300 — and future earnings.

When he died April 20, Simon was about 3½ feet long and weighed 20 pounds. Cook said he could have grown to weigh 40 pounds, likely making him larger than Simon's father and the world's biggest rabbit.