Fifty-three orang-utans are returning home after being forced to fight each other in a zoo in Thailand.
The apes had been dressed up as boxers and made to perform for tourists until Thai authorities rescued them in 2004.
Tests discovered that of the more than 100 orangs rescued, 53 originally came from Indonesia, and they are now being prepared to go home.
Pressure groups say smuggling apes is a big problem, and that at least 700 are taken from south east Asia every year.
The rescued apes will hopefully be returned to the wild, where they came from.
Orang-utans come from the islands of Sumatra and Borneo, where experts say only about 27,000 remain in the wild.
They are under threat as their forest homes are being cut down as well as being hit by the smuggling trade.