Part of the video released by the BUAV
An animal rights group has condemned the way monkeys in places like Cambodia are being caught for animal testing.
The British Union for the Abolition of Vivisection (BUAV) says the creatures are being hunted in jungles to be sold to science labs in America and China.
It says the way the monkeys are caught and kept in cages on monkey farms is causing the creatures suffering.
The group is calling for rules to be brought in so the creatures are treated in a better way.
The long-tailed macaque monkeys aren't endangered, so technically it isn't wrong for people to capture them from the wild.
But what's upset campaigners is the way they are being caught and transported.
The video released by the BUAV shows people chopping down trees and forcing the monkeys to fall into the river.
They are then captured in bags and sealed inside a container.
The group claims that eight out of 10 of the creatures die on their journey out of Cambodia because of the way they're treated.
Ricky talks to Michelle Thew from the BUAV
The BUAV has called on the Cambodian government to ban the capture of wild animals, and bring in more rules about the way creatures already in captivity are treated.
The group is also calling for Europe and America to stop imports of captured wild animals, and for better conditions at monkey breeding centres.