BBC have launched a probe into British sitcom Some Mothers Do 'Ave 'Em after one viewer complained about a homophobic slur.
The programme first aired in February 1973 and ran until December 1978, and was a hit with audiences at the time.
The series starred Michael Crawford as accident-prone Frank Spencer and his tolerant wife Betty Spencer, who was played by Michelle Dotrice.
The plot followed Frank's various attempts to hold down a job, which frequently ended in disaster.
The Christmas special, which aired in 1975, saw Frank working as a pixie in a festive department store grotto.
However, the language used in the episode has raised concerns, with the BBC investigating the series now.
The scene sees Frank say: "I'm the chief of the pixies, I'm the friend of all the little boys and girls."
A boy turned to the character and heckled: "Oh no you're not, you're a p**f."
"I beg your pardon, block your ears!" Frank replies in the scene.
The episode was recently repeated on BBC Two, which prompted a complaint from a viewer, leading to an investigation from the internal watchdog.
But before the episode aired, the BBC issued a warning, informing viewers that the episode contained outdated language.
According to The Times, an internal BBC watchdog ruled the episode did not breach editorial guidelines.
A BBC spokesman said: "Attitudes and language change over time and our approach is to tell viewers when a show includes something that may be offensive, inappropriate or outdated."
But Some Mothers Do 'Ave 'Em isn't the only series that is prefaced with a warning, as Little Britain, The League of Gentlemen, Blackadder and Peep Show all have them too.
It comes after BBC viewers slammed the film Grease when it aired back in January, accusing the John Travolta movie of being racist, homophobic, and including bullying language.
