A Subway worker has revealed how tuna and steak arrive at the restaurants ready to be made into sandwiches—as the chain faces questions over its fish.

A man claiming to be an employee of the chain has been sharing behind-the-scenes clips from the kitchen, revealing how the ingredients arrive in bulk.

Posting under the name Travis2official, he's uploaded multiple videos showing how he preps tuna, steak and chicken teriyaki.

Alongside a vomiting emoji, Travis2official captioned a video "this subway tuna," showing the packet it arrives in.

Dressed in Subway's uniform showing the "spicy" logo on the front of his T-shirt, he filmed a plastic pouch that has "flaked light tuna in brine" stamped on the front.

It's been declared dolphin safe, and another label reads "for foodservice only," while it's revealed to be a product of Thailand. The ingredients listed are tuna, water and salt.

Travis2official films himself pouring the contents into a bowl, which he then breaks apart with a gloved hand.

Next in the clip, which has amassed more than 500,000 views, he pours in mayonnaise, from another plastic bag, before mixing it all together with his hands.

Subway is currently embroiled in a lawsuit over its tuna, with questions raised over what its fish products actually contain.

Plaintiffs Karen Dhanowa and Nilima Amin filed an action on January 21 that claims the foodstuff is in fact "a mixture of various concoctions that do not constitute tuna, yet have been blended together by (Subway) to imitate the appearance of tuna."

However they recently amended their position, and a new filing from June now focuses on whether the dish was "100% sustainably caught skipjack and yellowfin tuna."

Recent lab analysis commissioned by The New York Times found "no amplifiable tuna DNA was present in the sample and so we obtained no amplification products from the DNA."

An article published on June 19 quoted the results, continuing: "Therefore, we cannot identify the species."

Subway's website has issued a statement addressing the claims, saying: "The testing that the New York Times report references does not show that there is not tuna in Subway's tuna. All it says is that the testing could not confirm tuna, which is what one would expect from a DNA test of denatured proteins.

"The fact is Subway restaurants serve 100% wild-caught, cooked tuna, which is mixed with mayonnaise and used in freshly made sandwiches, wraps and salads that are served to and enjoyed by our guests.

"The taste and quality of our tuna make it one of Subway's most popular products and these baseless accusations threaten to damage our franchisees, small business owners who work tirelessly to uphold the high standards that Subway sets for all of its products, including its tuna."

And addressing the amended action, Subway continued: "Just like the original claim, the new claims are untrue and have absolutely no merit."

Meanwhile another video shared in April revealed how the steak is prepared, with Travis2official captioning the clip "just to let y'all know how subway steak looks. Behind closed doors."

The on-screen video caption, which has amassed more than 9 million views, added "how Subway steak come," along with a vomiting and a laughing crying emoji.

The video shows a block of meat, resembling a loaf of bread, which has a use-by date of February 2022 stamped on the plastic.

The next shot shows the steak in its trademark metal tub, and while wearing gloves Travis2official uses his hands to break apart the meat into chunks ready to be sprinkled onto bread.

Subway's steak and cheese wrap and sub, and the chipotle southwest steak and cheese contain the meat, with the former described online as: "Our Steak & Cheese Signature Wrap is a double portion of shaved steak, wrapped up with melty American cheese in a tomato basil wrap."

Subway's website lists the steak ingredients as "seasoned beef (beef, water, salt, modified corn starch, sugar, dextrose, sodium phosphate, tomato powder, yeast extract, natural flavors, natural brown color blend (vegetable juice color, turmeric), lemon powder (maltodextrin), garlic powder, onion powder, hydrolyzed corn protein, citric acid)."

The revelation didn't go down well with customers, with Jess writing: "Subway workers have got to stop posting. I don't need to know what's in it."

Kaden Randazzo pointed out: "Well it's shredded steak what u expect."

Adonis asked: "Ya'll expect real steak."

While Josh Rhodes commented: "Wouldn't even feed that to my dog."

In his last revelatory video, Travis2official defrosts a bag of chicken in some water, before coating it in the restaurant's signature teriyaki sauce, ready to be spread on bread.

Newsweek has reached out to Travis2official and Subway for comment.

A photograph of a Subway sandwich.
A tuna sandwich from Subway is displayed on June 22, 2021, in San Anselmo, California. A worker has revealed how their tuna sandwiches are made amid claims the filling doesn't contain any tuna. Justin Sullivan/Getty Images