Kate Hansen, 21, of Burbank, Calif. -- a member of the U.S. Olympic luge team -- said she shot the video after spotting the animal roaming the dormitory where athletes are staying during the Sochi Olympic Games.
She uploaded it to YouTube, writing, "I'm pretty sure this is a wolf wandering my hall in Sochi," WNYW-TV, New York, reported.
It was unclear whether the animal was, in fact, a wolf or just a large dog, the report said.
Syndicated TV show "Inside Edition" reported Thursday the video was a hoax, set up by Kimmel with Hansen's cooperation.
USLA spokeswoman Sandy Caligiore confirmed it, telling "Inside Edition" plans called for Hansen to talk with Kimmel via Skype during the taping his Thursday's late-night ABC-TV show.