Ncuti Gatwa has shared an emotional post thanking his co-star companions after leaving the show.

Gatwa's 15th Doctor regenerated in Saturday's finale (May 31), and regenerated into the returning Billie Piper.

In a statement provided by the BBC, the Scottish-Rwandan actor said the "journey has been one that I will never forget".

Now, he has shared a social media post thanking co-stars Millie Gibson and Varada Sethu.

Gatwa regenerating in his final episode of Doctor Who (Image: BBC Studios/Bad Wolf/PA)

Gibson played Ruby Sunday and was the main companion in Gatwa's first series as the 15th Doctor.

Her character appeared less frequently in the second series, with Varada Sethu's Belinda Chandra taking the mantle as the new companion.

Taking to Instagram, Gatwa shared a picture of the trio, and said: "Three queens of the sky,

"Twas an experience like no other and thank God we were by eachothers side.

"There aren’t quite the words for how much you both mean to me but I am so grateful I got the opportunity to work, learn from and laugh with you both everyday.

"You’re both just simply incredible and it has been nothing short of a blessing to share this journey with both of you.

© South Wales Argus