Glass has been found in some jars of Sainsbury's olives, the supermarket giant has said.
A small number of jars are involved and, as of Friday, there has been a product recall as a precautionary measure.
A spokeswoman said: "Glass has been found in a small number of jars of by Sainsbury's 350g green pitted olives. We take food safety very seriously and have removed them from sale as a precautionary measure. We are asking customers to return jars with a best before date of 13/1/17 to a Sainsbury's store for a full refund."
She said the company was working closely with the supplier and an investigation was under way as to how the incident had happened.
It was understood that no one had been injured or taken ill through eating the olives.
Sainsbury's was alerted to the issue through receiving a small number of customer complaints - it then removed the product from display and issued a public recall.
It was understood that the number of jars in which glass was found was in single figures.
Sainsbury's was unable to say how many jars had been removed from sale.