Boris Johnson's fiancee Carrie Symonds urges more shops to ban coconut products made from monkey labour

Prime Minister Boris Johnson's fiancee Carrie Symonds has welcomed pledges by four British retailers to stop selling coconut products that use monkey labour in their production, and urged others to do the same.

Key points: An investigation by PETA Asia showed use of pigtailed macaques to harvest coconuts

An investigation by PETA Asia showed use of pigtailed macaques to harvest coconuts The products include certain brands of coconut water and coconut milk

The products include certain brands of coconut water and coconut milk Britain's largest retailer Tesco said its coconut products are not made using the practice

Symonds, a conservationist, was responding to a report in the UK Telegraph that highlighted the use of pigtailed macaques taken from the wild in Thailand and used on farms to scurry up trees and harvest coconuts.

The report cited an investigation by the animal rights organisation PETA Asia.

"Glad Waitrose, Co-op, Boots & Ocado have vowed not to sell products that use monkey labour, while Morrisons has already removed these from its stores," Symonds tweeted.

She called on all other supermarkets to stop selling the products, which include certain brands of coconut water and coconut milk, and named three major chains.

Walmart-owned Asda said it was removing Aroy-D and Chaokoh branded products from sale while it investigated the report with its suppliers.

"We expect our suppliers to uphold the highest production standards at all times and we will not tolerate any forms of animal abuse in our supply chain," it said in a statement.

Conservationist Carrie Symonds (right) used social media to urge retailers to stop selling the products. ( Reuters: Toby Melville )

A spokeswoman for Sainsbury's said it was actively reviewing its ranges and investigating the issue.

"We are also in contact with PETA UK to support our investigations," she said.

Tesco, Britain's biggest retailer, said its own-brand coconut milk and coconut water did not use monkey labour in its production and it did not sell any of the branded products identified by PETA.

"We don't tolerate these practices and would remove any product from sale that is known to have used monkey labour during its production," a spokesman said.