Lakyn Taite-Allen took to Facebook to share her disgust, sharing a picture of the half-eaten burger with the post: "Went through Lincoln Road McDonald's today and received this unpleasant surprise - a bite out of my Big Mac!"

The customer slammed the fast food chain, calling the meal an 'unpleasant surprise' and shared her disappointment on the service from the particular branch.

Allen, from Auckland, New Zealand, had ordered the popular meal from a drive through branch of the chain while with relatives.

Local media reported she was shocked to find not only a chunk taken out of it but that the burger was cold.

"Went back to find out how this happened, not back in to get a refund or another burger, but more an explanation and all the manager could say was it's "impossible for this to happen as if I had tampered with it or something. Well guess what, I received not even an apology or an explanation," she said.

Stuff.co.nz reported that McDonald's has since apologiszd to the customer about the incident after a review of the kitchen's cctv showed the burger had been returned by a previous customer and then accidently resold to Taite-Allen.

"Whilst we consider this to be an isolated incident, we have taken the opportunity to reinforce with our crew the importance of following McDonald's standard operating procedures," a McDonald's spokeswoman said.

"When followed, we are confident these procedures assure that our food products are of a high quality."

Lakyn Taite-Allen was reportedly pleased to have been given an explantion, but was concerned that staff training was not stringent enough to stop it from happening.

"I believe the situation could have been handled a lot differently from the beginning. I'm just so glad I didn't give it (the Big Mac) to my little brother. I think if any child got it they wouldn't really have thought about it they would just eat it," she said.