Which? tested 28 toys bought from Amazon Marketplace, AliExpress, eBay and Wish, and found 12 posed a safety risk after failing one or more tests.

Each product was tested against British safety standards and checked for small objects that could pose a choking risk, sharp edges and points, cords or fabrics that could pose a strangulation risk, and magnets and batteries that could be easily accessed.

In total, researchers found 50 safety failures among the 12 toys that failed tests, with 10 toys presenting a choking risk and two posing a strangulation risk for children. Which? also found two toys that had either magnets or batteries that could be easily accessed, which could cause serious injuries to children if swallowed.

Five of the products that failed tests were sold on Wish, making it the worst offender. Three were sold on eBay and AliExpress, and one was available on Amazon Marketplace.

The most dangerous product Which? found was a 51-piece doctor’s playset, described as a toy for a baby or toddler, sold on Wish. It was filled with unsafe toys and had at least 20 choking hazards. Most of the toys in the set broke into small and dangerous parts far too easily, including play scissors and a notepad which revealed sharp points.

A Wish spokesperson said: “All merchants on our platform are required to adhere to local laws and safety standards where their goods are sold. In the rare instance where a product falls foul of those standards, it is promptly removed and, where appropriate, the merchant in question faces a potential suspension from the platform.”

A similar doctor’s set sold on AliExpress was also filled with dangerous toys and failed tests. Which? identified 10 potential choking hazards and also found the long cord on the doctor’s coat could present a strangulation hazard.

An AliExpress spokesperson said: “As a marketplace based business, the sale by merchants of products that violate the product listing policy of AliExpress is prohibited. We have policies and procedures to identify violations and take action. We will continue to take action against sellers who violate our terms of use.”

A set of magnetic building blocks aimed at children aged three years old and above and sold on Amazon Marketplace also failed safety tests.

Which? shared its investigation with the four online marketplaces and all 12 products that failed have since been removed from sale.

Unlike UK retailers, online marketplaces have limited responsibility for ensuring the products sold on their platform meet legal safety requirements, repeatedly allowing unsafe toys and products to make it onto their sites.

The Office for Product Safety and Standards is currently reviewing the product safety system, including regulation of online sales. Which? believes that online marketplaces must be given greater legal responsibility for the safety of products sold on their sites so that consumers are far better protected from dangerous and illegal items.

Sue Davies, Which? head of consumer protection policy, said: “Many parents will be appalled by our research which has revealed that some toys bought from online marketplaces are failing to meet safety standards and could pose a serious safety risk to children playing with them.

“Consumers should be able to trust that products sold in the UK are safe and meet the standards required, yet a woeful lack of checks and monitoring by online marketplaces means dangerous toys are entering people’s homes.

“It is absolutely crucial that online marketplaces are urgently given greater legal responsibility for the safety of products sold on their sites so that consumers are far better protected from dangerous and illegal items.”