Step by painstaking step, Benedict Cumberbatch is transformed from Sherlock star to Frankenstein’s monster.

These behind-the-scenes photographs reveal the two-and-a-half hour process the actor went through to become the Creature in Danny Boyle’s stage version of Frankenstein.

The images come from a new app, which is being released as the award-winning show returns for cinema screenings.

Cumberbatch shared the role with Jonny Lee Miller, with each actor playing Frankenstein and his Creature on alternate nights of the show’s 2011 run at the National Theatre.

Miller went through the same make-up process as Cumberbatch — although it took less time because he had a shaved head.

The app also includes previously unseen interviews with the two actors at the start of the run, in which Miller reveals it would have been too physically demanding to perform the play if they had not shared the roles.

He said: “We couldn’t do it eight shows a week, not the way we’ve decided to go about it. It’s given us licence to go about it in a slightly lunatic fashion.”

He also said he had never before performed a play which left him “absolutely drenched and panting”. Cumberbatch, who spent 40 minutes after each of his shows as the Creature having his make-up taken off, said the transformation was “very painful sometimes”.

The actors are seen discussing people’s expectations of Mary Shelley’s classic story and how playwright Nick Dear’s adaptation focuses on the voice of the Creature.

The app is being launched as cinema screenings of Frankenstein return today for the third time in response to public demand.

Nearly 98,000 cinema-goers saw the play when it was broadcast live. Another 243,242 watched it at encore screenings in 35 countries including Kazakhstan, Costa Rica and China.

For more visit www.ntlive.com or get the app here