Makers of Quorn Meat Free Mince fear the 300g packs from the freezer compartment sold exclusively through supermarket giant Tesco could be a safety risk.
Vegetarian brand Quorn Foods Ltd had been endorsed by four time Olympic gold medallist Mo Farah up to last year.
The Food Standard Agency are urging customers who may have bought any one of the 12,000 £1 packs of mycoprotein at Tesco not to use them but return them for a full refund.
It said: "Quorn Foods Ltd is recalling a batch code of its frozen Meat Free Mince because it may contain small pieces of metal. This product was only sold at Tesco.
"The product may contain small pieces of metal which could represent a safety risk.
"Quorn Foods Ltd is recalling the above product from Tesco stores.
"A point-of-sale-notice will be displayed at Tesco stores."
Customers who have bought a 300g packet of the mince with a best before end date of 31st August 2018 are encouraged to take them back to the store.
A spokesperson from Quorn said: "Quorn has recalled 12,000 packs of its Frozen Quorn Mince 300g (date code 136331 BBE 31/8/18) as a precautionary measure.
"The product recall is limited to Tesco stores only and any products purchased prior to 27 February are not affected by this product recall."
Marlow Foods Ltd said: "Quorn can confirm that on Tuesday 28th February 2017 we recalled 12,000 packs of Frozen Quorn Mince 300g (date code 136331 BBE 31/8/18).
"This immediate recall is a precautionary measure once we became aware that the single batch in question may contain small pieces of metal resulting from an isolated production issue.
"The safety and wellbeing of our customers is our number one priority, which is why we instigated this recall as soon as we became aware of the issue.
"The product recall is limited to Tesco stores only and any products purchased prior to 27 February 2017 are not affected by this product recall.
"No other packs of Frozen Quorn Mince 300g beyond the 12,000 under recall and no other Quorn products are affected.
"We would stress that this recall relates to a single batch of a single product on sale via a single retailer for less than two days from a single distribution depot.
"Customers are advised not consume the product and should return it to their retailer for a full refund."