Nestle has recalled four varieties of Kit Kat Chunky bars after pieces of plastic were found by seven people.
The company said the 48 gram Peanut Butter, Hazelnut, Choc Fudge and Caramel flavour chocolate bars were being recalled "to avoid any risk whatsoever to our consumers".
Kit Kat Chunky Collection Giant Eggs were also being called back.
Nestle advised consumers not to eat the products and return them unopened for a full refund.
A spokesman said: "The safety and quality of our products are non-negotiable priorities for the company.
"We sincerely apologise to our consumers for any inconvenience caused by this voluntary recall."
Kit Kat is one of Nestle's top-selling brands, with 150 bars consumed worldwide every second, according to the BBC.
The affected chocolates are:
- Kit Kat Chunky Peanut Butter (48g) with a best before date range of September 2013 to February 2014.
- Kit Kat Chunky Hazelnut (48g) with a best before date range of September to October 2013.
- Kit Kat Chunky Choc Fudge (48g) with a best before date range of September to October 2013.
- Kit Kat Chunky Caramel (48g) with a best before date range of June to July 2013.
- Kit Kat Chunky Hazelnut Multipack with a best before date range September to December 2013.
- Kit Kat Chunky Collection Giant Egg with a best before date of July 2013.
Consumers wanting more information can telephone Freephone (land line only) 0800 604604 (from UK) or 00800 6378 5385 (from ROI) from 8am to 8pm from Saturday March 23.