Retail giant Amazon is continuing to sell baby sleep positioners despite fears they can cause babies to suffocate.
Several other firms, including John Lewis and Tesco, have removed the products from their websites after US authorities issued a fresh warning to parents saying they were unsafe.
The US Food and Drug Administration (FDA) has linked the products to at least 12 baby deaths in America - which occurred when babies rolled from their side to their front and suffocated.
The positioners, sometimes called nests or wedges, are intended to keep the baby in one place on their back and are marketed as suitable for use up to six months of age.
Some parents use them hoping their baby will sleep longer due to the infant feeling cosy, while others believe they cut the symptoms of reflux.
While some retailers have taken action to remove the products from their websites, others, including Amazon and Jo Jo Maman Bebe, still have them for sale.
A spokeswoman for Jo Jo Maman Bebe said it was still selling the products but was "investigating the issue as a matter of urgency with our suppliers".
A spokeswoman for Amazon, which still has a range of sleep positioner products for sale, said the firm would not be commenting on the issue.
John Lewis has removed the Cocoonababy Sleep Positioner from sale.
It still has a range of "nests" and "pods" for sale including the Cocoonababy nest and the Sleepyhead.
John Lewis told worried customers on Twitter that both of these products are not considered sleep positioners and are therefore still on sale.
A statement from John Lewis said: "We have one baby sleep positioner and as a precautionary measure we are removing it from sale."
A Tesco spokesman said: "We have removed these products from our website as a precautionary measure."
Several of the products were still available on eBay but a spokeswoman said it was planning to remove them.
She said: "Following recent recommendations by US authorities, items of this nature will now be prohibited from being sold on our platform.
"Our team will be informing sellers and removing any listings that contravene our policies."
Mothercare has also removed some products from sale.
Individual manufacturers are still selling the products via their websites.
A statement from the FDA said it was "reminding parents and caregivers not to put babies in sleep positioners".
"These products - sometimes also called 'nests' or 'anti-roll' products - can cause suffocation (a struggle to breathe) that can lead to death," it said.
"The two most common types of sleep positioners feature raised supports or pillows (called 'bolsters') that are attached to each side of a mat, or a wedge to raise a baby's head.
"The positioners are intended to keep a baby in a specific position while sleeping and are intended for infants under six months old."
The FDA and the NHS recommend that infants sleep on their backs on a flat mattress in an empty crib.
The FDA said its safety advice was to "never use infant sleep positioners. Using this type of product to hold an infant on his or her side or back is dangerous".
"The federal government has received reports about babies who have died from suffocation associated with their sleep positioners," it said.
"In most of these cases, the babies suffocated after rolling from their sides to their stomachs.
"In addition to reports about deaths, the federal government also has received reports about babies who were placed on their backs or sides in positioners - but were later found in other, dangerous positions within or next to these products."
Mothercare said it had removed the Babymoov Cosy Dream sleep positioner from sale.
A statement from the Lullaby Trust baby charity said: "There are hundreds of baby sleep products on the market and parents assume that if something is for sale it is safe to use.
"We do not recommend wedges and sleep positioners as evidence shows that the safest way for a baby to sleep is on a firm, flat mattress, in a clear cot free of pillows, toys, bumpers and sleep positioners.
"Babies are at higher risk of sudden infant death syndrome if they have their heads covered and some items added to a cot may increase the risk of head-covering and can also increase the risk of accidents.
"We recommend that, while evidence on individual products is not widely available, parents do not take any chances and stick to scientifically proven safer sleep guidelines."
A spokeswoman for Boots said: "At Boots UK, the quality and safety of the products we sell is of the utmost importance to us.
"We are removing the sale of all sleep positioner products whilst we investigate further with our suppliers."