Bob the Builder has been accused of swearing on a children's video.
The cartoon character appears to let rip twice when he loses his temper while decorating.
HIT Entertainment, which makes the TV series, launched an inquiry after parents complained.
It now insists Bob did not say "F*****g hell" and Bob is simply "muttering".
However production was halted and a new version put out of Bob's White Christmas, which features the voice of Neil Morrissey and has sold 250,000 copies in 13 months.
Carolyn Clayton was among those who protested about an episode called Wallpaper Wendy.
Her three-year-old son Charlie was given the tape for Christmas and she left him watching it with twin brothers, Conell and Luke, eight.
Carolyn, a shop assistant, said: "One of the twins came running in saying "Mum, Bob's swearing".
"I played it back and couldn't believe it. He does it twice, I was absolutely horrified. "
The 32-year-old, of Dunstable, Beds, added: "I've played it to a number of people and they all say the same thing."
Last night, a HIT Entertainment spokeswoman at first said Bob was simply mumbling but later claimed he was saying: "Oh, I don't know. I thought this was going to be easy."
She said: "We had the master tape stripped down to remove the background noises and that shows he's not swearing. He's just muttering. "