The Bowen Tourist Information Center said staff arrived for work Monday and discovered the sculpture -- which weighs 7.7 tons and is worth $81,369 -- was missing from its usual spot in front of the center, the Brisbane Times reported Monday.
Bowen Tourism chairman Paul McLaughlin said security video footage shows at least six people using heavy equipment and cranes to cart off the Big Mango between midnight and 2 a.m. Monday.
"It wouldn't have been an easy thing to shift, but someone's done a pretty good job of borrowing it," McLaughlin told Fairfax Media.
McLaughlin said he was not angry about the theft, which some have theorized may be a publicity stunt orchestrated by the Banjo Advertising firm in Sydney.
"At the end of the day it's a bloody big mango and I'm sure someone will see it and we'll find it anyway," he said. "I think it'll definitely turn up, no doubt about that. We're not sure what has happened but I'm sure we'll get it back."