Burger King has been slammed for cooking its newly launched halloumi burger in the same fryer as its chicken and fish dishes.

Vegetarians were eager to try the £3.99 cheesy offering upon its release in the UK earlier this week, following a successful trial in Sweden.

But while the fast-food chain promotes the fried cheese patty as a 'meat-free' option, its small print warns that the product is cooked in the same oil as chicken and fish.

Many customers were outraged after discovering the firm's frying approach and took to Twitter to complain.

Burger King has been slammed for cooking its newly launched halloumi burger (pictured) in the same fryer as its chicken and fish dishes

One upset individual wrote: 'Just went to try the new halloumi burger, lucky I read the very small print because it is fried in animal fat and I'm a vegetarian.

'Very misleading and I presume your chips are the same. IT'S 2019 GUYS.'

Another said: 'The halloumi burger from Burger King is fried in the same oil as chicken and I am fuming.'

'What is the point in having a "vegetarian" burger when it's NOT vegetarian and the halloumi is fried in animal fat. Go hard or go home,' a third added.

'Okay guys I'm gutted,' another Twitter user admitted. 'Went all the way to Burger King for the new halloumi burger, double checked it was veggie and was told that it's fried in the same fryer as the meat products.'

While the fast-food chain promotes the fried cheese patty as a ‘meat-free’ option, its small print (pictured) warns that the product is cooked in the same oil as chicken and fish

Reaction: Many customers were outraged after discovering the firm's frying approach and took to Twitter to complain

Despite diners' outrage, the halloumi burger was never described by Burger King as 'vegetarian', with the fast-food chain instead using the term 'meat-free'.

The company does offer a veggie burger, which is cooked separately from meat products as the patty isn't fried.

MailOnline has contacted Burger King for comment. A spokesperson told Metro: 'At this moment in time we're not operationally able to facilitate separate fryers and oil filtration systems in all of our restaurants.

'However this is a focus for us and our team are actively looking into solutions for how we can change this in the future.'

The halloumi burger is served up in a buttery brioche bun with freshly cut crisp lettuce, onions, tomatoes and creamy mayo (stock photo of halloumi)

The halloumi burger is served up in a buttery brioche bun with freshly cut crisp lettuce, onions, tomatoes and creamy mayo.

It will set you back £3.99 for a single patty burger (£5.99 as a meal) or £5.49 if you fancy two of the crispy fried cheese patties (£7.49 as a meal).

Customers can also hack the menu and get it added onto a Whopper or other meaty burger.

Halloumi has long-been a popular meat-free alternative for vegetarians.

The UK is now considered one of the biggest importers of the squeaky Cypriot cheese, consuming over 2,000 tonnes per year.