A climber spotted the bones on Thursday, and tucked them away to a spot he thought was secure, said Laurel Clegg, manager of the identification and disaster response unit of the B.C. Coroners Service.
He also flagged the remains and alerted authorities, said Clegg.
But when the recovery team arrived on Saturday, some of the bones were gone.
"It is quite unusual," said Clegg.
"It was probably somebody thinking they were helping ... or who didn't realize what [the remains] were."
Clegg said the remains are "really important" for an investigation, and the coroners service is hoping to retrieve them.
She wouldn't comment on when the person died, their identity, or whether the death was related to a previously reported climbing accident.
There's no reason to think someone purposely stole the remains, said Clegg. They were far from a public path, in an area accessible only to skilled climbers and mountaineers.
"The B.C. Coroners Service would like to stress that there is no suggestion that this person or persons had any improper motives, nor that they are in any legal difficulty as a result," the agency stated a press release.
Anyone who might have information about the remains is asked to call the Metro Vancouver regional coroner at 604-660-7731 or text the Whistler-Squamish coroner at 604-815-3567.