An episode of Fireman Sam in which a character appeared to tread on a page from the Koran will not be investigated by the broadcasting watchdog.

In an episode from series nine of the popular children’s animation, a character carrying a tray of hot drinks slipped after tripping on some paper on the floor of the fire station. Several sheets fly into the air, one of which looks to be covered with Arabic script.

Ofcom received 170 complaints about the episode but said that it could not be confirmed that the episode featured the Koran.

An Ofcom spokesman said: “We received a number of complaints about a character appearing to trip on a piece of paper that might have contained text from the Koran. After careful assessment, we won’t be investigating.

An actor dressed as Fireman Sam at the Brockwell Park fireworks display, 2014An actor dressed as Fireman Sam in 2014 (David Parry/PA)

“We studied a recording of the programme in the highest possible resolution. We found that the page did appear to contain Arabic text, but its contents could not have been deciphered, nor recognised as being from a given text.”

HIT Entertainment, which produced the show, previously apologised “unreservedly” to viewers for the episode, shown on Channel 5.

The programme first aired on October 8 2014 and was available to watch online at any time on the My 5 video on demand service. It was last shown by the broadcaster on Milkshake, its children’s breakfast show, on June 28.

The company, which produces brands including Bob The Builder, Pingu and Thomas The Tank Engine, blamed the animation studio for the mistake.