A BBC Panorama investigation has exposed retail giant Amazon for selling £3.99 car seats on its global selling platform.
One of the products in question was the £3.99 "Infant Safe Seat" which claimed to protect children in the case of a hard break.
All three online retailers have now removed the controversial safety equipment from their sites.
How dangerous are the seats?
According to the BBC, a case back in 2013 found that these products would rip to shreds during an impact of just 30mph. After tests, Trading Standards officers nicknamed the products as "killer car seats".
Surrey Trading Standards was alerted and Amazon removed the products in 2013, but it looks like they are back on the digital shelves.
In 2019, Which? Magazine also found that the fabric based seats, used to save a child's life during a car-collision, also lacked safety labelling.
Speaking to the BBC, Alex Neill from Which? said: "Parents will be horrified at the thought they could be unwittingly putting their child's life at risk with one of these 'killer' car seats. Online marketplaces cannot continue to turn a blind eye to dangerous and illegal products being sold on their sites.
These items were deemed suitable for newborns up to 5 years old children.
In a statement, Amazon said: "Safety is extremely important to us and we regret that these products were available from third-party sellers using our stores.
"After a thorough investigation, we identified the issue and are removing these products, and we're also contacting each customer who purchased one of these products to explain the situation and issue a refund".
How to check car-seat safety
Only EU approved car seats can be sold in the UK. To check the safety regulations of your child's car seat look for a clear orange label with codes ranging from EVE R44-03, EVE R44-04, or ECE R129. This means they have been thoroughly tested and regulated to EU standards.
If your seat does not have this coding, then it should not be legally sold in the UK.
Amazon said: "All sellers must follow our selling guidelines and those who don't will be subject to action including potential removal of their account. The products in question are no longer available."
Which? has campaigned for an Online Harms Bill that will make Amazon responsible for illegal or faulty products being sold via their site. Currently, the giant retailer has no legal responsibility for products sold by third-party companies.
Amazon: What they know about us, is aired tonight at 8.30pm on BBC One.