Rifat Asghar, 42, was eating a carrot and sweetcorn meal from the supermarket in Bradford, Yorkshire, for lunch when a colleague spotted a matted lump of fur.
On closer inspection, Ms Ashgar identified a leg and a tail – as well as what looked like an eye.
She took the salad back to the shop where she claims she was offered a £5 voucher.
An email from a team leader at the supermarket, said the specimen was sent for testing at a lab in London, which revealed it was a young common weasel.
The email said: ‘The specimen was very badly damaged, showing some skin, fur, a leg joint, a foot and tail.
‘It was concluded that the complaint specimen was most likely the remains of a young member of the species Mustela nivalis, the weasel.
‘It was not possible to determine where the specimen could have originated from due to the lack of distinguishing features.
‘It is in the opinion of Insect Research and Development Limited that as these weasels would not usually come indoors, the specimen may have been accidentally harvested with one of the components of the salad.
Geeze, they may not have apologized, but they did offer the whiner £5