BBC World Service’s investigation unit, BBC Eye, has uncovered a global monkey-torture ring stretching from Indonesia to the United States. As a result of a year-long investigation, BBC Eye found hundreds of customers in the US, UK and other countries, paying people in Indonesia to torture and kill baby long-tailed macaques on film.

The torture ring began life on YouTube before moving to private groups on the encrypted messaging app Telegram. BBC journalists went undercover in one of the main Telegram torture groups, where people were coming up with extreme ideas and commissioning people in Indonesia to carry them out.

In The Monkey Haters, the BBC hunts down and confronts the perpetrators and sets out to find Mini, a baby monkey at the heart of this torture ring.

Police are now pursuing the buyers and several arrests have already been made.

With exclusive access to law-enforcement in the UK, the US and Indonesia, the investigation asks vital questions about why social-media platforms such as YouTube and Telegram continue to carry illegal content of animal abuse. And the BBC Eye investigation reveals the fate of Mini.

The Monkey Haters, from the BBC World Service, is available for viewing in the UK – via BBC iPlayer and on BBC Three – and internationally, on BBC World Service YouTube channel, from 00.01 BST on Tuesday 20 June (23.01 GMT on Monday 19 June). The documentary will be available in Indonesian via the BBC News Indonesia YouTube channel from 10.00 Jakarta Time (03.00 GMT) on Tuesday 20 June. The radio version will be available via BBC World Service. UK audiences can also listen on Radio 4 as part of File on 4.

Read the full story on the BBC News website.

The BBC World Service’s BBC Eye investigation is by Astudestra Ajengrastri, Joel Gunter, Rebecca Henschke, Sam Piranty, Kelvin Brown

Executive producers: Monica Garnsey, Mustafa Khalili

Editor: Marc Perkins