As he posed with his two sons near the resort of Klosters eight days before his wedding, the prince muttered: "Bloody people. I can't bear them," the BBC reported.
The assembled microphones picked up his comments, mumbled to his sons, which included: "I hate doing this".
Charles' communication secretary has denied he has contempt for the media.
The Prince's fiancee Camilla Parker Bowles cannot ski and was not on the holiday.
Asked how he was feeling before the April 8 wedding, Charles said: "I'm very glad you have heard of it." But then he muttered: "Bloody people."
Turban for Charles, sari for Camilla
When Prince William was asked about the wedding he said he was "very happy, very pleased", adding: "It will be a good day."
Charles' communication secretary Paddy Harverson said Charles had not been looking forward to the photo call.
"He prefers it when he skis and he just wanted to get up into the mountains. He doesn't have contempt for the media," he said.
Referring to images published today in British newspapers of William and his university friend Kate Middleton at the resort, Harverson said: "A few paparazzi yesterday got the holiday off to a bad start. I think the prince was a little bit upset about that."