Earlier this month, a man spotted an unwelcome creature at the bakery section of the supermarket store on Garratt Lane.
“I saw this rat at the bakery counter in Sainsbury's supermarket southside. The staff were not fussed and carried on when I informed them,” he said.
He shared a photo from July 16 of the small animal, peeking out from behind a trolley.
Sainsbury's said cleanliness is important to its stores and it is looking into the issue.
A spokesperson said: “We have strict hygiene processes in place and are investigating this report”
