A mum-of-two claims she found several pieces of "metal wire" inside nappy from Lidl while changing her toddler son.
Stacie Yeats said she noticed a "hard lump" in the unused nappy as she was about to put it on her one-year-old son, Remi.
The 26-year-old claims she put the Lidl Lupilu nappy to one side and put a different one on Remi before going back to inspect the "lump".
Stacie, from Arbroath, Angus, alleges she found metal wire inside the nappy and fears her son could have been injured if she had put it on him.
Lidl has launched an investigation into her claims.
Stacie said: "I had bought a pack of nappies earlier that week which are the same ones I've used for over four years with my older son too.
"I was changing my youngest son's nappy when I felt a hard lump in the nappy.
"I changed my son with a new one and then opened up the nappy with the hard lump only to find bits of metal.
"I immediately threw all of the nappies in the bin because I was so shocked what I found."
She added: "I couldn't stop thinking about what would have happened if I didn't notice it - I worry that the metal could have cut his back open.
"I want to make people aware that this has happened and make people extra cautious and not naive about what could be in their child's nappy."
A spokesperson for Lidl said: "We take product safety very seriously, and for this reason metal detectors are used during the production of our nappies, to prevent foreign bodies from entering the product.
"We were, therefore, extremely concerned to learn of this matter and are very sorry for any distress this may have caused.
"We can confirm that an urgent investigation was launched with the supplier as soon as the customer got in touch, and our quality assurance team will continue to keep the customer updated on the outcome of this."
