Supermarket chain Tesco has started an investigation after a woman found a 3in (7.6cm) lizard in a bag of fruit.
The animal was found in a bag of Costa Rican bananas sold at a supermarket in Colchester, Essex.
Tesco said: "Our suppliers do all they can to remove this kind of risk through rigorous and thorough processes.
"With all the expertise, checks and will in the world, however, it is not always possible to completely legislate for the natural world."
In May, law graduate Fernando Rossaggo, 27, of Greenstead, Essex, found a worm inside a Scotch egg she had bought from Tesco, in Colchester.
Ms Rossaggo returned the egg to Tesco, which said it would send the product to the manufacturer for an investigation.
A Tesco spokesman said at the time: "We take all complaints very seriously.
"This is very surprising so we'll send the item to the supplier to investigate as soon as we receive it."