Scottish TV chef Gordon Ramsay has opened up on the worst item he has ever found on the popular show Kitchen Nightmares.

The Fox show saw the Johnstone-born chef, 55, visit restaurants across the UK and USA that were struggling to bring in customers, serving badly-tasting food, or dealing with serious hygiene issues - often all three. 

In a 2019 interview on Hot Ones, Gordon was asked by host Sean Evans: "What's been the most disturbing thing that you've ever seen unnoticed or uncared at a restaurant on Kitchen Nightmares?"

Gordon said: "It's a really good question.

"So, I went into a refrigeration unit once and saw a tartar sauce that was three and a half years out of date.

"How f***ing dumb do you have to be to use this tartar sauce that stank.

"To use a sauce that was festering, bubbling. Like something that's out of f***ing Harry Potter that was off three years ago."

Kitchen Nightmares truly lived up to its name with some of the discoveries Gordon has made, such as tables covered in dust and dirt, unwashed dishes, and pantries full of mouldy food. 

In one episode, Gordon watched as a chef dropped a piece of chicken, picked it off the floor, and continued to cook right in front of him.

Discussing other experiences, the Michelin starred chef added: "Several Stuart Littles spotted in the corner of the kitchen.

"Yeah big motherf******, they're like cats.

"I didn't know the owner had cats, he didn't. It was the f***ing rats.

"Pretty shocking. From rats to mould."