Hilton acquired her exotic new pal last weekend on a trip to Las Vegas. She and the wild tree dweller are now back in Los Angeles, where the critters are forbidden. They also are illegal in New York City.
If she won't give it up, the hotel hottie could be hit with a misdemeanor.
"We'll send them a letter just to let them know we're aware they have a restricted species," said Steve Martarano, spokesman for the California Department of Fish and Game.
Hilton will have to either get rid of her kinkajou or move to a state that allows them. But it's not easy to find an animal sanctuary, so sometimes the only option is to have it killed, Martarano said.
Hilton rep Elliot Mintz insisted, "Paris is a law-abiding citizen. If she receives a letter from the Fish and Game people, I'm sure it will be reviewed and acted upon accordingly."
Meanwhile, animal activists and kinkajou experts blasted Hilton for keeping the South American rain-forest animal as a pet.
"They'll tear an apartment down pretty fast, but they're just being kinkajous," biologist Dr. John Gittleman said. "In nature, they go from tree to tree, so in your house they may go from window to window or drape to drape."
Hilton, a fan of cute little animals, totes her trademark Chihuahuas to red-carpet events, and recently owned a ferret.
"It seems she thinks animals are as disposable as her friends and fiancés," fumed Lisa Lange, of People for the Ethical Treatment of Animals. "The ferret is now gone, and we think the kinkajou is not long for her home either, based on her past treatment of her pets du jour."