A woman claims to have found a lizard in a packet of bananas which she bought at a Tesco store in Shropshire.
Natasha Oliver said she took the bag back to the site in Shrewsbury, and was given an apology and an 80p refund.
Tesco said its growers work hard to inspect fruit carefully, and noted that it would update her on the findings of its investigation.
Oliver told BBC News that on 26 September, she picked up "a bunch of bananas in the packaging" whereas she would "usually go for the loose - so it was kind of my mistake".
She added: "I opened them and saw that there was a creature inside. It scared the life out of me, I screamed my head [off] and I'm surprised that nobody came running to my house.
"(There was) a dead lizard inside. It wasn't very nice to see at all. I'm just very glad that I didn't put it in my daughter's lunchbox, because it could have hurt her really."
A Tesco spokesperson said the retailer had apologised to Oliver.