In the seventh episode of the ninth season, one of the characters is holding a tray full of hot drinks. The character then slips on a pile of papers on the firehouse floor. Some of the papers fly up into the air, including one which appears to be a page from the Quran.
Muslims have responded furiously, causing several television stations - including British Channel 5 - to pull the episode.
The episode was first aired on October 8, 2014, and has been available for On Demand users since then. However, it was only after it was re-broadcasted a few weeks ago that someone noticed the alleged page from the Quran.
A spokeswoman for Hit Entertainment, the company which produces the show, has apologized, saying "The page in question was meant to represent a piece of paper with unreadable text on it, and we are sorry for the mistake. We apologize for offending the sensibilities of our viewers, and for the insult this caused."
She continued, saying "we will no longer be working with the animation studio which his responsible for this mistake. Additionally, we will immediately remove the episode from the network and will look in depth into the production process to make sure that this type of mistake won't happen again."