High Street chain Argos is recalling five car seat models made by the nursery products brand Mamas & Papas.
It has told parents to stop using the seats "immediately" over safety fears.
It is feared the models may not protect children in the event of a crash, with their shells cracking under impact.
The affected models are Mamas & Papas Mercury Group 1 Black, Mercury Group 1 Grey, Mercury Group 1-2-3 Black, Mercury Group 1, 2, 3 Grey, Mercury Group 2-3 Black and Grey.
Mamas & Papas said no incident had been reported to it related to any of the recalled car seats, which it makes solely for Argos.
In a statement Mamas & Papas added: "We continue to work closely with Argos to determine the exact nature of the issue.
"All Mamas & Papas car seats are tested, certified and approved under the European regulations R44/04 by independent accredited bodies."
'Return for refund'
Argos said in a statement: "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."
It said that any customers who had bought one of the seats "should immediately stop using the product" and return it to an 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 Argos catalogue numbers of the affected car seat models are 297/7526, 411/9100, 305/6037, 397/9530, and 245/4829. press here for webpage