Several supermarkets have removed some coconut oil and water from their shelves after it emerged, the products were made from monkey-picked fruit.
The monkeys are snatched from the wild and trained to collect up to 1,000 coconuts a day, People for the Ethical Treatment of Animals (Peta) said.
The animal rights group said that pig-tailed macaques in Thailand were treated as “coconut harvesting machines.”
In response, Waitrose, Ocado, Co-op, and Boots promised to stop selling some products.
Meanwhile, Morrisons said it has already removed products made from coconuts collected by monkeys from its shelves.
In a statement, Waitrose said: “As part of our animal welfare policy, we have pledged never to knowingly sell any product from monkey work.”
Co-op said, “As an ethical retailer, we do not allow the use of monkey labor to obtain ingredients for our products.”
In a previous tweet on Friday, Prime Minister Carrie Symonds’ fiancee, a conservationist, called on all supermarkets to boycott the products.
Subsequently, Sainsbury’s told the BBC: “We are actively reviewing our ranges and investigating this complex problem with our suppliers.”
Asda said: “We expect our suppliers to meet the highest production standards at all times and will not tolerate any form of animal abuse in our supply chain.” He vowed to remove certain brands from his shelves until he has investigated the allegations of cruelty.
Ms. Symonds then returned to Twitter to urge Tesco to make a similar promise: “Come on @Tesco! Come to you! Please stop selling these products too,” he wrote.
Tesco did not immediately respond to the BBC’s request for comment.
1,000 coconuts a day
Peta said he had found eight farms in Thailand where monkeys were forced to collect coconuts to export worldwide.
Male monkeys can collect up to 1,000 coconuts a day, says Peta. It is believed that a human can choose around 80.
He said he also discovered “monkey schools,” where animals were trained to pick fruit, as well as ride a bike or play basketball for the entertainment of tourists.
“The animals in these facilities, many of which are illegally captured as babies, displayed stereotypical behavior indicative of extreme stress,” said Peta.
“The monkeys were chained to old tires or confined to cages that were barely big enough for them to turn.”
“A monkey was seen in a cage in a van frantically shaking the bars of the cage in a futile attempt to escape, and a monkey screaming with a rope desperately tried to escape from a handler.”
In one case, the organization was told that the monkeys would have their canine teeth pulled out if they tried to bite the handlers.
“These curious and highly intelligent animals are denied psychological stimulation, companionship, freedom and everything that makes life worth living, all so that they can be used to collect coconuts,” said Peta’s director, Elisa Allen. .
“Peta is asking decent people to never support the use of monkey labor by avoiding coconut products from Thailand.”