Alan Cumming Offers $10,000 Reward to Find 'Buddy' Chimpanzee Costar Who Mysteriously Vanished

“It’s horrible to think he might be in a cage in a dark basement somewhere or have met some other fate, so I’m appealing to whoever knows what has become of him to please come forward,” said the actor

Photo: Ron Galella, Ltd/Ron Galella Collection via Getty

Alan Cumming is teaming up with PETA to help find his former costar, a chimpanzee named Tonka, who mysteriously disappeared.

Cumming, 57, and Tonka starred together in the 1997 family comedy, Buddy, which is based on the true-life story of Gertrude Lintz, a 1920s socialite who raised monkeys as part of her family.

"During the months we filmed together, baby Tonka and I became good friends, playing and grooming each other and just generally larking about," Cumming said in a statement.

Continued the Tony Award-winner: "It's horrible to think he might be in a cage in a dark basement somewhere or have met some other fate, so I'm appealing to whoever knows what has become of him to please come forward and claim the reward."

Sean Zanni/Patrick McMullan via Getty

Cumming has pledged to match PETA's $10,000 reward for information about the whereabouts of the chimp, raising the total to $20,000.

According to PETA, Tonka was last seen in a cage at the former Missouri Primate Foundation (previously known as Chimparty) – "a notorious, now-defunct breeding facility in Festus, Missouri that bred baby chimpanzees, rented them out for movies and parties, and sold them to private owners."

"If you know where Cumming's former costar may have been shipped to, sold, or hidden away, PETA wants to hear from you," PETA Foundation Deputy General Counsel for Captive Animal Law Enforcement Brittany Peet said in a statement. "If he's still alive, Tonka deserves to live out the rest of his days surrounded by chimpanzee friends at a lush sanctuary, as ordered by the court, and someone out there might be able to help PETA get him there."

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PETA had previously sued the Missouri Primate Foundation over the living conditions of chimpanzees housed there, and was granted permission to rescue Tonka, along with six other chimps, and transfer them to a sanctuary.

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When the organization went to carry out the court's order last July, Tonka had vanished, and owner Tonia Haddix said he had "died," PETA said in a statement.

In January, a judge found that Haddix's testimony was not credible, and now, PETA and Cumming are trying to find the beloved chimpanzee, the animal rights organization added.

Haddix did not immediately respond to PEOPLE's request for comment.

Anyone with pertinent information should call PETA at 757-622-PETA or submit their tip at PETA.org/Tonka.