The So Solid Crew rapper-turned-actor first revealed that he is appearing in a 2013 Doctor Who episode in September, admitting the he got in trouble for tweeting images of the shoot.
Walters has now revealed to Radio Times that his Doctor Who instalment - said to be called 'Journey to the Centre of the Tardis' - centres on an exploration of The Doctor's blue box.
"In our episode, it'll be the first time people get to see so much of the Tardis," he hinted.
Walters went on to praise Doctor Who star Matt Smith and Jenna-Louise Coleman, who plays the Time Lord's new companion.
"You can't beat being in Doctor Who - it's something I've grown up with my whole life and working with Matt Smith was amazing," the star revealed. "He's a really, really good actor and just being a part of that huge BBC franchise was an incredible thing.
"And Jenna-Louise Coleman is really good at what she does - it seems like she's enjoying her job and I loved working with her."
Coleman makes her official debut as The Doctor's companion in the Christmas special, which will air later this year in the UK and the US.
