Doctor Who
The Doctor (Peter Capaldi) and his companion Bill (Pearl Mackie) arriving in early 1800s London. BBC

Doctor Who showrunner Steven Moffat has confirmed that the BBC sci-fi drama is delving into the issues of race and whitewashing in series 10 episode 3.

Speaking to TV Guide, the 55-year-old television writer and producer explained he is seizing the opportunity to make a point about race in Thin Ice, which airs on Saturday ( 29 April), as portrayals of Britain in 1800s always lacked diversity.

"History is always whitewashed," he said. "How do we manage to have a diverse cast despite that? The way that we did it was... [to just] say that you will see people of different colours there. In fact, there were. People all didn't arrive in the twinkle of an eye. It is bending history slightly but in a progressive and useful way."

In the last instalment Smile, the timelord and his companion Bill arrived in 1800s London where they were faced with the frozen Thames. This weekend's action will pick up from there and the subject of race will be tackled head on as a mixed-race Bill worries about how she will be received.

"The way that we did it was... [to just] say that you will see people of different colours there. In fact, there were. People all didn't arrive in the twinkle of an eye. It is bending history slightly, but in a progressive and useful way."

"Also, it wouldn't be a pleasant place for [Bill] in several respects. Taking that on is just respectful of the audience really."

Steven added: "[The episode is] a chance to... I'm always reluctant to sound so pious and so do-gooding and all of that. It's useful that these things are talked about. The evil in Doctor Who can sometimes be the evil in our real world, too."

The current series of show has already garnered praises for the introduction of new gay companion Bill Potts, played by Pearl Mackie.

Mackie previously said that said it was "about time" the iconic show, hailing it a small victory for LGBT groups. She added of her alterego: "[Being gay] is not the main thing that defines her character – it's something that's part of her and something that she's very happy and very comfortable with.

Doctor Who continues on Saturday (April 29) at 7.20pm on BBC One.