A council has stopped supplying books intended for babies after discovering plastic film on the back of mirrors.
The mirrors are in the back of the This Little Baby board book, part of a Bookstart Baby pack.
Herefordshire Council said it stopped supplying the affected books as soon as they were alerted to the potential danger.
It is feared the plastic could pose a choking hazard to babies if it is swallowed.
Some have already been delivered and parents are urged to check their books, a spokesman said.
He said the council had been alerted to the problem by the Bookstart Trust.
A trust spokesman said: "A protective plastic film covering the small pretend mirror on the inside back cover should have been removed by the manufacturer but was not and therefore poses a potential choking hazard."
All stock is being checked, he added, and professionals and council staff were being asked to alert families.