Argos has warned parents to stop using certain car seats "immediately" as it issued an urgent recall over safety fears.
The retailer has recalled five products from upmarket brand Mamas & Papas.
It is feared the models may not be able to protect children in the event of a crash, with their shells cracking under impact.
In a statement, it said: "We have identified a potential safety concern. In the event of an accident the car seat shell may crack and therefore not provide the intended level of protection to the user."
Argos is offering a full refund to customers, saying: "If you have purchased any of the seats, you should immediately stop using the product and return the car seat to your local Argos store for a full refund.
"We wish to thank you for your co-operation and apologise for any inconvenience caused by this recall."
The affected models are:
:: Mamas & Papas Mercury Group 1 Black (Argos catalogue number 297/7526).
:: Mamas & Papas Mercury Group 1 Grey (Argos catalogue number 411/9100).
:: Mamas & Papas Mercury Group 1-2-3 Black (Argos catalogue number 305/6037).
:: Mamas & Papas Mercury Group 1, 2, 3 Grey (Argos catalogue number 397/9530).
:: Mamas & Papas Mercury Group 2-3 Black and Grey (Argos catalogue number 245/4829).