Boxes of Quaker Oats have been pulled from stores because of the presence of moth pupae and larvae.
The affected packs were sent to stores in the north of England
The firm has withdrawn about 750 of its 1kg cartons containing a free measuring cup, after the infestation was found.
The boxes were sent to Tesco and Sainsbury's stores in the north of England from depots in Middlewich, Cheshire, and Haydock, Merseyside.
Quaker Oats is advising customers not to eat affected batches, which have the best before date 11 August, 2007.
"There is no known health risk from these pupae and larvae but obviously we wouldn't advise anyone to eat them," said a Food Standards Authority spokesman.
No other Quaker Oats products are known to be affected.