England's Children's Commissioner says Amazon should ensure "disgusting" child sex dolls are not restored for sale on its website, after a BBC investigation found them for sale on its platform.
About a dozen child sex dolls were found for sale on Amazon Marketplace.
After the BBC contacted Amazon about one doll it was removed, but three days later it was back on the website.
Amazon said it had now removed all the specific products which the BBC drew to its attention.
In a statement Amazon said: "All Marketplace 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."
Responding to the BBC investigation, Anne Longfield, England Children's Commissioner, said: "These dolls are disgusting and are clearly meant to look like children.
"Not only do I, as Children's Commissioner, but the wider public also, have a right to expect a huge company like Amazon, to not only remove these products from their platform, but to explain why they are on there in the first place and ensure they can't just be reloaded having been taken down.
"Such dolls are clearly built for one purpose and that purpose is a clear danger to the safety of real children," she added.
The UK Border Force has seized 179 child-like sex dolls since March 2016 as part of Operation Shiraz, a special operation set up in conjunction with the National Crime Agency.
In July 2017, a judge ruled child sex dolls were obscene items and therefore covered by the 1979 Customs and Excise Management Act.
However, it is not a criminal offence to manufacture or possess a child sex doll: individuals can only be charged for importing them.
Amazon Marketplace is an area of the retailing website where third party businesses can sell products.
Amazon does not sell the products itself but instead receives money from the sellers.
Dolls found on the website were typically three or four feet tall with waist sizes around 16 inches (41cm).
In the accompanying pictures they were placed in sexual poses with descriptions such as "Mannequin Sexy" and "100% mimics girl's body".
Several dolls were described as coming with "sexy lingerie".
A couple from Durham were horrified to find that a child sex doll came up in the results for their online search for sex toys.
"We felt disgusted and we straight away reported it to Amazon," they told the BBC.
Twenty four hours later the couple had received no response from the retailer.
The NSPCC has warned use of the dolls can lead people to harm children.
Designed to be as lifelike as possible, they are made of a silicone type material and weigh as much as a child.
The dolls are made in such a way as to enable sex acts to be performed on them.
The head of policy at the children's charity NSPCC, Almudena Lara, highlighted the danger child sex dolls can pose to children.
She told the BBC: "We already know that there is a risk that people using these dolls could become desensitised and their behaviour could become normalised to them, so that they go on to harm children, as is often the case with those who view indecent images of children online.
"There is absolutely no evidence that using the dolls stops potential abusers from abusing children.
"Until gaps in the law are addressed to make it illegal to make, sell or distribute them, retailers like Amazon should refuse to sell these vile dolls," she said.