A Cornish biscuit firm thought it had a real cookie monster on its hands when clotted cream shortbread mysteriously started to go missing overnight.
Cookie had been living above the office for up to a month
But instead of a greedy employee the culprit eventually caught taking the biscuit at Furniss' Redruth office was actually a hideaway cat.
It is thought Cookie, as he has been nicknamed, had been living above the office for up to a month.
He is now being cared for by the RSPCA at the Venton Animal Centre.
Furniss technical manager Sharon Williams said: "As we are a company who makes biscuits, we always have a plentiful supply up in our offices, for our staff to enjoy with their coffee breaks.
"But when we discovered one of the boxes appeared to have been clawed open we stopped blaming each other for eating them all."
The company called in a pest control firm who gave it a clean bill of health.
But staff continued to notice that the biscuits were disappearing from the office overnight and several weeks later the frightened cat was spotted during an early evening forage for biscuits.
Reunite with owner
The cat was caught by RSPCA animal collection officer Felicity Cross.
She said: "There are not many homes in the area so we believe this cat may have arrived on the back of a lorry.
"There are business in the area that trade up and down the county, so Cookie could have come from a home from anywhere in the South West, or indeed the country."
Now the RSPCA is appealing for information in a bid to reunite Cookie with his owner.