The US authorities are hunting for Ryan Alexander Jenkins her boyfriend, a reality TV contestant, who on Thursday was charged with her murder.
Miss Fiore had her fingers and teeth “forcibly removed”, prosecutors said.
Mr Jenkins, 32, is thought to haev slipped into Canada after driving and power-boating more than 1,000 miles from southern California after the corpse of Miss Fiore was found in a suitcase dumped in a rubbish bin in Los Angeles on Saturday.
“The victim had been badly beaten, all of her fingers had been cut off, and all of her teeth had been forcibly removed,” said a statement from the California prosecutors.
Canada said its security forces were looking for Mr Jenkins.
Police believe Mr Jenkins reported her missing on Saturday night – after her body had been found – and then disappeared when detectives said they wanted to talk to him.
Mr Jenkins was a contestant on the VH1 reality show Megan Wants a Millionaire, a US television show in which men with a net worth of at least $1 million vie to win a woman seeking to become a “trophy wife”. He is variously described as an architect, property developer and investment banker.