Leading Thousand Guineas hope Chriselliam has been put down after failing to recover from a foot infection.

The Charlie Hills-trained daughter of Iffraaj won the Fillies' Mile at Ascot last season, earning a trip to the Breeders' Cup.

She excelled at Santa Anita where she streaked clear under Richard Hughes to win the Juvenile Fillies Turf in tremendous style.

Former champion jockey Willie Carson was one of her owners along with music mogul Chris Wright.

Last month Hills revealed that Chriselliam had been suffering from a poisoned foot. At the time Hills was confident she would be able to continue her racing career.

"It's a shocker," Hills said.

"Basically she split her shoe and we thought we had it under control but she took a bad turn and it got reinfected.

"The antibiotics weren't working and it spread to her pedal bone. The vets tried everything. It's been a long month for us all.

"She'd been a wonderful patient and never lost her appetite. It's very sad for everyone involved and I'd like to thank all the vets who tried to save her.

"Unbelievably the trophy for the Breeders' Cup only arrived today."

A dual Group One winner, Chriselliam amassed nearly STG500,000 ($A915,918.67) from just six races.