They fed live cats to pythons, photographed the act and uploaded it on Facebook.
The three men are believed to be snake charmers from Kuala Lumpur.
The video was so repulsive that cat lovers from around Malaysia have lodged more than 30 police reports against the men over the photographs.
The animal lovers want action to be taken against the men for animal cruelty. The photographs have since been deleted, The Star reported. The incident happened in Malacca this month.
Manager Intan Nuraida Rahman, 34, who lodged a report on Wednesday, alleged that the men had written in their Facebook post on Jan 5 that the cats were collected from the streets and fed alive to the snakes.
She also alleged that there were pictures of the men throwing the cats into the pythons' cage and of them watching the snakes attacking and swallowing their prey.
"The pictures are repulsive," she said.
Malacca Society for the Prevention of Cruelty to Animals chairman Vincent Low said this could finally explain a two-year "mystery" behind cases of missing cats in the state.
He added: "We have told our counterparts in Seremban, Johor Baru and Kuala Lumpur to be on the alert for missing cats as this issue is not confined to Malacca."
Kuala Lumpur/Selangor Cat Lovers Association chairman Rezan Thamby said they were waiting for more members to lodge police reports before they press for action against the three men.
Said Mr Rezan: "When we confronted them, they denied having fed the cats to the snakes."
He said the pythons will be sent for tests to see if they had indeed eaten cats.
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