Oliver Hallam was bought the KFC chicken meal by his step-mother Krystal Henderson as a treat.
But when he bit into what he thought was a piece of chicken, it was rock hard.
On closer inspection his appalled step-mother realised that it was actually a piece of blue hand roll.
Ms Henderson, a nursery nurse from Gosforth, Newcastle, said: I got a shock. "I thought the actual chicken had gone off. All it was inside was deep fried blue roll.
"Realising it was blue roll was worse than chicken. If it was bad chicken they might have just had a bad batch or something, but the blue roll could have been used for anything - it could have bleach or disinfectant on it. "
"I didn't know where the blue roll had been because it was screwed up. Had someone wiped their hands on it, had it been used to wipe the floor?
"To give that to a child, I felt so guilty even though it wasn't my fault. For a child to bite into that is horrendous.
When Oliver bit into the 'chicken' it was rock hard [SWNS]
"When he bit into it, it was rock hard. He pulled it out of his mouth and when he did, it pulled away the batter - you could see the blue roll inside.
"If you bite into something that awful you are just taken back."
The mother-of-two had purchased the £1.99 takeaway chicken meal for her and her step-son to eat at home.
But after the shocking incident, she returned to the Killingworth restaurant to complain, only to be told to call customer support.
The 29-year-old said: "I was traumatised by it - I was really upset.
"I went back into the store crying and they said I had to call customer service.
"I had to keep ringing them and keep following it up. It felt like I had to do all the work when it was their mistake.
"I work full time and I'm a mother. I just don't have the time to keep chasing them up and ringing around. After what has happened, I shouldn't have to."
After their horrible find, neither Oliver nor his step-mother plan on eating at KFC again.
Ms Henderson was unimpressed with the way her complaint was handled [SWNS]
Ms Henderson said: "Oliver is only seven but he knows exactly what was going on and he doesn't want to go to KFC again.
"He didn't eat anything for the rest of the week. He completely lost his appetite. He wasn't unwell or grumpy, just lost his appetite."
After an investigation, KFC apologised to Krystal and offered her a free meal.
A letter to Ms Henderson read: "The blue tissue has most likely originated from a tissue roll used for KFC hygiene purposes.
"The store assume it must have fallen unseen into the breading lug that is under the sieve and was not noticed by the cook."
A spokesperson for the franchise that operates KFC in Killingworth said: "We're very sorry for Ms Henderson's experience and apologised to her immediately, as well as giving her a refund at the time of the incident.
"We take food quality and hygiene very seriously and unfortunately, on this extremely rare occasion, our restaurant failed to meet the high standards that both we and our customers expect.
"We have retrained staff on our stringent food preparation procedures at this store to ensure this doesn't happen again."