Screaming in fear as they are violently shackled, these monkeys are traumatised as they suffer chemical testing after being transported by Air France. The shocking footage shows the helpless macaque monkeys being restrained and force fed with tubes shoved down their throats and up their noses. Chemicals are then pumped into their bodies and the distressing footage shows the panicked animals writhing in agony after being injected. The monkeys are then forced into tiny cages and held in plastic tubes where they can be seen desperately trying to escape as they are held captive. Scroll down for video . Terrified: These macaque monkeys are clearly traumatised as they are experimented on in a laboratory . Tortured: The monkeys are seen having tubes forced up their noses and down their throats to sedate them before the testing . Shocked: The footage shows the monkeys being tested on . The shocking scenes were caught on camera by People for the Ethical Treatment of Animals (PETA), as part of their protest against Air France being the only major carrier still shipping monkeys destined for experiments. Last year, more than 23,000 non-human primates were imported into the United States alone, PETA said. The monkeys are primarily crab-eating macaques, thousands of which are transported from Mauritius to laboratories in the United States and Europe. In the horrific footage, one lab technician even warns his colleague about her brutal treatment as she tries to insert the tube, and says: 'You're going to kill him.' But the woman angrily fires back: 'I'll ram it down his f***ing throat.' Many of the thousands of monkeys shipped from Asia and Africa by Air France were first torn away from their homes and families in the wild. The sensitive and intelligent animals are crammed into small wooden crates and transported inside dark cargo holds for nearly 30 hours, often on passenger flights just below unsuspecting customers. Restrained: With their arms and legs secured, the monkeys are also restrained at the neck to make sure they comply with the laboratory's demands . Panicked: The monkeys are held in plastic tubes where they can be seen desperately trying to escape as they are held captive . Caged: The macaque monkey are also forced into tiny cages where the lab technicians are seen forcefully handling them . When the monkeys reach their final destinations, they are imprisoned in tiny cages and tormented in painful, terrifying – and often deadly – experiments. The footage in the video was taken inside a for-hire laboratory, that conducts toxicity tests on monkeys in which they are force-fed chemicals pesticides and drugs. Previous footage  taken inside a laboratory that conducts toxicity tests showed monkeys being force-fed chemicals, pesticides and drugs. Many of the monkeys are also sold on to private companies and universities that poison, mutilate, cripple and kill them in cruel experiments. Previous videos have also shown monkeys that have suffered from rectal prolapse from the stress of being restrained, blackened lungs, trembling, collapse, bleeding and self-mutilation - including one animal who chewed its finger to the bone . Mimi Bekhechi, UK Director of PETA, said: 'By shipping thousands of monkeys to laboratories, Air France are just as responsible for the mutilation and death of these intelligent, social animals as are the experimenters who wield the drills, scalpels and syringes. Most major airlines in the world – such British Airways, American Airlines, Cathay Pacific, United  and dozens of others – refuse to take any part in the industry and prohibit the transportation of primates to laboratories. This week, the founder and managing director of renewable-energy company Ecotricity, Dale Vince sent an angry open letter to Air France calling on them to stop transporting the monkeys. Ecotricity, founded in 1996, began with a single wind turbine and now supplies thousands of people with green electricity. Outraged: Dale Vince, founder of renewable-energy company Ecotricity, has fired off an angry letter to Air France as the company continues to transport the animals . In his letter, Mr Vince points out that Air France are the only remaining major airline that still participate in what he describes as a sickening practice and says that his company will not fly with the airline. He joins a growing list of celebrities – including musician Peter Gabriel and TV presenter Chris Packham - who have spoken out against Air France's carriage of primates. Mr Vince wrote: 'Having previously flown with Air France, I was shocked to learn from my friends at PETA that you are the last airline that continues to ship monkeys to laboratories in the EU and the US. 'These highly intelligent, sensitive animals are either torn away from their homes and families in the wild or bred in squalid conditions on notorious factory farms in Asia and Africa. 'They are then shipped – by your airline – to laboratories, where they face even greater horrors, including being intentionally brain-damaged, shocked, addicted to drugs or force-fed chemicals, before they are finally killed. 'All this suffering, pain and fear occurs for experiments which – as articles in the prestigious publication BMJ have highlighted – fail to translate into effective treatments for humans. 'It truly sickens me to think that these terrified monkeys, crammed into tiny wooden crates for as long as 30 hours before they reach their final destination, are frequently flown in Air France cargo holds – right below the feet of passengers who are completely unaware that purchasing a ticket from your airline means that they are supporting this shameful trade and condemning these wonderful animals to death.' But an Air France spokesman told MailOnline the transportation of animals on its flights - which is dealt with by Air France Cargo - complies with current regulations. The company also holds an authorization to transport animals issued by the Ministry of Agriculture, certifying this fact. The spokesman added: 'The company has established strict standards in terms of comfort and well-being to ensure animals optimal conditions of transport. Primates travel to private research laboratories as well as public research laboratories . 'This highly supervised activity is paramount in the development of research and medicine in France and Europe.' Support: TV presenter Chris Packham (left) and rock star Peter Gabriel (right) have spoken out in the past about Air France's transportation of the animals . Campaign: PETA have called on Air France to stop transporting the monkeys to the laboratories around the world . The animals, and the conditions they are subject to, are also subject to random checks on breeding conditions and use. 'Worldwide, the use of primates for research is crucial in many medical areas,' the spokesman said. 'Research in diseases of the central nervous system, research in autonomic diseases like Parkinsons and Alzheimer's, research in psychological diseases like depression and addiction to alcohol, as well as research in infectious diseases like HIV, malaria, hepatitis C. 'As such, Air France management has received numerous letters of support from various public or private research institutes.'
Horrific footage shows crab-eating macaque monkeys caged for testing . Thousands of monkeys worldwide torn away from families and tortured . Air France are the only major international airline still shipping animals . People for the Ethical Treatment of Animals call on them to stop . For more detail on PETA's Air France campaign, visit: http://PETAUK.org/airfrance .