WARNING: DISTRESSING FOOTAGE
Footage has been released showing the horrific conditions suffered by monkeys at Europe's largest primate research centre.
The monkeys can be seen getting injected with sedatives and tattooed while they're conscious throughout procedures.
According to the MailOnline, campaigners say some were severely injured after their stressed cage-mates lashed out after being unable to cope with their surroundings.
The animals were sedated but remained conscious during procedures and were reportedly able to feel. Then when they were coming round from the injections they were left unattended and groggy, making them vulnerable to injury.
There was also footage of their captors singing The Offspring's 'Pretty Fly (For a White Guy)', seemingly having a good time with ADI saying they were 'oblivious to their plight'.
The monkeys would suffer injuries from fighting with their counterparts and when they were of no more use to the facility, it is alleged that they were put down in full view of their cage-mates.
Jane Goodall, the UN Messenger of Peace and Founder of the Jane Goodall Institute said: "The way they are being treated in the video is shocking and inhumane.
"It is my considered opinion that those involved in this kind of research on primates should consider using alternative procedures that do not involve experimentation on intelligent, sentient beings.
"This research should be phased out as soon as possible."
The Biomedical Primate Research Centre is Europe's largest facility, breeding animals for its own use and other laboratories, collaborating with researchers in the UK and the US.
According to the MailOnline, latest figures show that it has more than trebled its primate use, from 95 individuals in 2016 to 317 in 2017.
The facility has 1,600 primates, most of which are macaques kept in breeding groups of 20-40 individuals.
The footage was recorded in March 2017 and released on 1 September this year, which is international primate day.
People have been outraged by the video with one person writing on social media: "I can't watch that, what I will say is people who participate in those deeds are sadists, there's absolutely no need for it!"
Another added: "MONSTERS!!!! This must be what inspired the horror films about alien abductions, being probed and tortured by sociopathic aliens like pieces of meat.
"This is what these poor beings endure. It is beyond horrific. It is the stuff of the worst, most disturbing nightmares. I hope this video has the same impact on those with the power to stop it."
Featured Image Credit: Animal Defenders International