Kauto Star's owner Clive Smith has revealed that he is "90% certain" that the former Cheltenham Gold Cup winner will be retired.

The 12-year-old failed to finish the highly-anticipated Gold Cup challenge, which was won by Synchronised, ridden by Tony McCoy.

"The horse seems well in himself but I've had a word with Ruby [Walsh]," Smith said after the race. "He said he jumped the first really well and the second really well but when he went to the water jump he just stretched a bit and possibly felt a pain inside.

"Ruby didn't want to go on because of that, it was probably from the tumble he had two weeks ago. I think we probably will retire him. We said we wouldn't say anything today but I think it's a very good bet we'll do that.

"What a great career he's had and he's been a wonderful horse. I've been so proud to own him and also the support of everybody has been absolutely tremendous. I would say it's 90% certain that he'll be retired. Someone will have to come up with a very good reason for me not to retire him."

Kauto Star is the only horse to have won the Gold Cup consecutively.