Ncuti Gatwa, who plays Doctor Who, has stated that he had a talking down for his foul tongue on set.
The 31-year-old Sex Education actor was named Jodie Whittaker’s replacement as the Time Lord last year.
He made his debut appearance in the final of three recent specials, in which David Tennant returned temporarily to the character.
However, during filming the performance, the actor was chastised for using some colourful language while dressed up.
Ncuti later said that showrunner Russell T Davies had called him away for a conversation.
‘The only time I’ve ever gotten in trouble for anything was when I swore while wearing a Doctor Who costume,’ he explained.
‘I got called into Russell’s office. Woo! And he let me know that that’s not acceptable.
‘He said, “Do what you want when you’re out of costume, but when you’re in costume, do not let us catch you swearing”,’ he added when speaking to The Sun.
The actor previously told The Radio Times he was learning quickly on how to be a ‘PG role model’ after his run-on Sex Education
‘For the last four years I’ve been co-leading an X-rated show, and so I’m on a constant journey of learning what it is to be a PG role model and the lead of a family show,’ he told the Radio Times.
Over the weekend, he made his first appearance in the long-running saga in regeneration sequences that enthralled viewers.
While fans were aware that the third 60th anniversary special, The Giggle, would be David’s final appearance in the part, the manner in which he was sent out surprised many.
Many people were surprised by the story twist, which saw David and Ncuti’s Doctors coexist as two entities due to a unique regeneration.
‘OMG DOCTOR WHO!!! David Tennant AND Ncuti Gatwa the way I SCREAMED. It’s too much awesomeness on one screen,’ someone shared on social media.
Others claimed they were in tears while seeing what had now become their “favourite episode and regeneration that has ever happened.”
The Doctor meets mystical and enigmatic goblins in the forthcoming Christmas special, The Church on Ruby Road, as his life collides with new companion Ruby Sunday, portrayed by Millie Gibson.
Doctor Who’s 2023 Christmas Special airs on December 25 from 5.55pm on BBC One.