Apes are being forced to fight in staged boxing matches in front of crowds of tourists in Thailand.
Orang utans are dressed in silk shorts, given boxing gloves and put in a ring in a safari park to fight in pairs.
But after a British couple who were making a documentary discovered and filmed the bouts, animal rights groups described them as "incredibly cruel."
Alison Cronin, who filmed the fights to expose the problem, said: "It's very distressing to watch."
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