Brendan O'Carroll, the Irish star of BBC One sitcom Mrs Brown's Boys, has apologised for making a "clumsy" joke where a "racial term was implied" during rehearsals for the series' upcoming Christmas special.

The BBC temporarily suspended production of the series and launched an investigation, with the shows now going ahead as planned.

O'Carroll, who is also the show's creator, said he had made a "clumsy attempt at a joke" during a read-through of the scripts, where he was in character as Agnes Brown.

"It backfired and caused offence which I deeply regret and for which I have apologised," he told The Mirror newspaper.

Those present were said to have been "left shocked by the slur", The Mirror said, adding they "flagged it with the BBC afterwards". The corporation said it "acted immediately".

The episodes, filmed in the BBC's Pacific Quay studios in Glasgow, marked the first mini-series run since 2013.

The BBC said: "Whilst we don't comment on individuals, the BBC is against all forms of racism, and we have robust processes in place should issues ever arise."

The programme, first shown on BBC One in 2011, has had four series and has long been a fixture on the BBC's Christmas TV schedules.

It won a National TV Award last month for best comedy.

The slapstick show stars O'Carroll as a foul-mouthed Irish matriarch, who is "mammy" to her surrounding family and friends, who gather for laughter and tears in her kitchen and living room.

It has a pantomime theatricality to it, featuring shots of the audience and including moments when the actors corpse - a term used to describe breaking character and laughing - and ad-lib on stage.

Last month, at the National TV Awards, O'Carroll told The Sun: "It’s hard to believe this Christmas Day episode will be our 50th episode."

He added: "I think we’re going to be doing another mini series for April, but whenever the BBC broadcast them."

Speaking about the award, he told the newspaper it was "tremendous, to get this award is our sixth".

"It’s voted for by the audience and viewers. This is the icing on the cake it’s amazing," he added.

Although it is not necessarily a universal hit with TV critics, the show has proved to be an enduring success with its fans.

Dick Fiddy, archive TV programmer at the BFI, told the BBC in 2020 he thought it "thrived in the gulf between critics and audiences... because there's a certain section of the audience that feels disenfranchised by modern comedy; an audience that enjoyed the broad, double entendre comedy of On The Buses and Are You Being Served?"

O'Carroll has said the success of the show has been, at least in part, down to an audience" that has felt "left behind", as TV comedy has evolved and changed.