CBeebies character Mr Tumble has been accused of saying “I’m f****** you” on air in sign language.

The presenter, aka Justin Fletcher, opens each of his Something Special programmes with a gesture meant to mean “I’m happy to see you”.

However, according to The Sun, he is provoking anger by mixing it up with a similar sign.

One parent told the paper it had caused confusion between him and his daughter. Jamie Miller, from Yorkshire and who also works for the Royal National Institute for the Deaf, said: "The signs for “happy” and “f******” are quite similar but it was still an awful error to make.

“Katie, who is learning sign language, asked what the gesture meant. I didn’t know what to tell her.”

In British Sign Language, says the paper, “happy” translates to gently brushing the palms together while the swear word is achieved by brushing the area between the thumb and first finger together.

However, the BBC denied there was a mistake and said the mix-up was because it used a system called Makaton, not British Sign Language.

Kate Sidwell, from the RNID, commented: “We advised the BBC that using Makaton would cause confusion. Makaton is used more for children with learning difficulties — it is essentially a different language.”