KFC bosses have promised to investigate complaints against its Bracknell branch after customers slammed the restaurant as dirty with undercooked food and poor service.

Some customers have claimed the Bagshot Road branch, the only KFC in Bracknell, it is the worst one they have visited and say the main speciality, chicken, is often rubbery and chips undercooked.

Despite it being the first branch in the country to undergo a total modernisation and refurbishment in 2014, management at the branch has been criticised for the slow service, incorrect orders and its bad attitude towards customers who complain.

Speaking to the News, KFC customer and father-of-four Mark Looker agreed it was the worst KFC he had ate in.

A post he started on Facebook has gained more than 170 comments, most agreeing with his complaints.

He said: "Everyone says its shocking.

"The last time I went in they gave me undercooked chips and wouldn't give me a refund, the manager told me there was nothing wrong with the way they ran things.

"It's the worst one I've been to, and I go to a lot of KFCs, in Camberley, London, everywhere."

He also criticised the cleanliness of the branch saying tables are often covered in food and the toilets smell, despite the branch's sticker for a level five hygiene rating.

Mr Looker added: "It's the only KFC in the town, everyone has to go to it if they want one and some people have said they've had bad stomachs after eating there."

Among the commenters on Facebook was Anton Yoshi Mercieca who said: "Chips are always cold. Orders are 60 per cent of the time wrong, chicken is always dripping with grease and buns are always hard."

Tania Waite added: "It's rank and has actually put me off KFC for life."

Others were more sympathetic to the branch with Karl Goold-Ainsworth adding: "Surely it depends when you go you may have just been unlucky and caught the end of the last batch. I've had bad meals from there and it's been changed for me when I've told them."

The branch was the first of more than 800 restaurants in the country to undergo a total revamp in 2014, with modern decor and new seating to give it a more "homely feel".

Now, nearly two years on, bosses say they will look into the complaints.

A KFC spokesperson said: "We're really disappointed to see the comments that have been left about our Bracknell restaurant. We'd like to reassure all our customers in Bracknell that we’ll be looking into this urgently, and will make any changes needed to ensure this restaurant reaches the high standards we expect at KFC."