The seats affected were sold through Asda, Tesco, Shop Direct and some independent retailers.
They were also sold through the Mamas & Papas website and factory stores.
Safety checks have shown that, in the event of an accident, the car seat shell may crack and therefore not provide the intended level of protection to the user.
The seats affected are Mamas & Papas Nembus, Mamas & Papas Aureus, Mamas & Papas Group 123, Mamas & Papas Altair.
All are Group 123 car seats. You can identify the seat by checking the orange label on the back - the approval code is 04 44596.
Mamas & Papas said none of the affected car seats had been on sale since March 2015 and stressed there had been no reports of any incidents involving any of the affected car seats.
If you have purchased one of the affected seats, you should immediately stop using the product and contact Mamas & Papas Customer Services team on 03332 412154.
A designated courier service will collect the car seat, and you will be issued with a refund or replacement.
Alternatively, you can take your car seat into a Mamas & Papas store and obtain a refund or a suitable replacement product.
Please note, proof of purchase is not required. If you purchased your car seat from Asda, Tesco or Shop Direct (Littlewoods & Very), please still contact Mamas & Papas directly.