SAN FRANCISCO (AP) -- Police are investigating the brazen theft of a beloved squirrel monkey named Banana Sam from the San Francisco Zoo.

The 17-year-old primate disappeared late Thursday, and investigators believe someone stole the animal, San Francisco police Sgt. Michael Andraychak said.

"It was apparent someone broke into the zoo and deliberately took the animal, we believe somebody has him," Andraychak said.

A reward, initially offered at $1,000 for Banana Sam's safe return, has been increased to $5,000 thanks to a pledge from a private donor, zoo spokesman Danny Latham said late Friday.

Who else? Poor critter will probably be held for ransom, which will be used to finance Chongo's terrorist "American Primate Party."