A McDonalds customer claims he was vomiting for days after he bit into a 'red raw' burger.
Byron Thomas, 28, was left with a peculiar taste in his mouth when he took an almighty bite out of his quarter pounder with cheese.
When he glanced down, he noticed the burger was cooked on the outside but raw inside.
"I spat it out of my mouth straight away, it was absolutely disgusting," he told UK media.
The father-of-two said he was sick for days and blames his brief encounter with the fast food treat for his upset stomach.
"I was up being sick at 4am the next morning and I am still ill on and off now," he said.
The furious customer complained to staff at the Northampton branch who offered to serve up another meal.
Outraged by the restaurant's burger blunder, Mr Thomas has vowed never to return to the chain.
"We only pop into McDonalds for a treat every now and then but there is no way me or any of my fiends or family will ever be going there again," he said.
'I have Ulcerative Colitis so it doesn't help my stomach when I am eating completely raw meat."
The fast food giant launched an investigation after Byron complained to head office.
A spokesman issued the following statement:
"Food safety is our highest priority. We place great emphasis on quality control and follow rigorous standards in order to avoid any imperfections in our food.
"We are disappointed to hear of this experience and as soon as we were made aware of the incident, we launched a full investigation. We will be in touch with Mr Thomas once that is complete."
Morning news break – February 12