Canadian actress Pamela Anderson spoke to reporters in Australia on Wednesday, shortly before surprising the contestants in the Big Brother house. (Paul Broben/Getty Images)

Canadian actress Pamela Anderson burst onto the set of the new Australian edition of Big Brother on Wednesday, surprising the participants of the long-running reality-TV program.

The 41-year-old actress is doing a three-day stint in the Big Brother house, though unlike the competitors will not remain confined to the house where it is set.

A current task assigned to the contestants is to photograph celebrity impersonators. When Anderson first appeared behind a glass screen, the housemates believed it was simply a look-alike.

Jaws dropped however, when the Ladysmith, B.C.-born star strode out of the set's so-called diary room.

Speaking to reporters before her appearance on the show, Anderson quipped that the sum she received for the gig was "huge, a lot … much more than I am worth."

She also revealed that cameras from her own forthcoming reality show, Pam: Girl on the Loose, would be following her Big Brother exploits as well.

Australian media have noted that Anderson — best known for her 12 Playboy covers and stint on the TV lifeguard series Baywatch — was enlisted in an attempt by broadcaster Channel Ten to boost Big Brother's flagging ratings.

Anderson also told reporters that her Australian plans also included visiting a local KFC restaurant to protest against the fast-food retailer (which is, incidentally, a major sponsor of the show).

Created by Netherlands-based Endemol, the Big Brother reality-TV franchise isolates contestants from the real world inside a camera- and microphone-filled house, where they must remain until voted out of the competition by the viewing public. Different international editions air around the world.