Bill Roache was a guest on the show

The BSC said the gun looked realistic, but ITV insisted it was clearly a toy.

The offending sequence came as part of a comedy scene in an episode broadcast in June 2001.

Donnelly was seen conducting a light-hearted interview with Roache, but co-host Ant McPartlin kept interrupting him.

'Not real'

Roache pretended to get increasingly annoyed by being referred to by his screen name, and stormed off with McPartlin - at which point Dec drew the plastic gun and shot him.

"The gun in the scene was a plastic toy pistol and clearly not real," a spokesman for ITV said.

"While we respect the viewers' concerns on gun crime, we did not believe the sketch represented a real life situation and this would have been recognised by the majority of viewers."

But the BSC decided that it was wrong to portray the use of a gun in a show that was mainly watched by children and teenagers.

Ratings

"The panel considered the depiction of the firearm had been realistic and demonstrated how effective use of a gun could be in controlling situations," their ruling said.

Ant and Dec have had hits with Saturday morning shows SM:tv and cd:uk as well as Pop Idol, which they host.

Slap Bang was less of a success, with poor ratings and lukewarm reviews, but a new series is due later this year.

Last year, the pair fell foul of the Independent Television Commission after showing partly-masked nudity on another tea-time entertainment programme, Ant & Dec's Secret Camera Show.