PETER CAPALDI was forced to hide the fact he knew his new Doctor Who co-star Pearl Mackie recently, in order to keep her casting a secret.

The actor, who plays the Time Lord himself, went to see The Curious Incident Of The Dog In The Night-Time earlier this month, which stars the actress and his soon-to-be on-screen companion.
After being invited behind-the-scenes to meet the cast, the 58-year-old had to pretend he and Pearl, 28, had never met before.

Speaking at a Doctor Who event at London’s Cartoon Museum, Peter commented: “I wanted to see the show but I didn’t expect to be asked backstage to meet everyone.”
The TV star continued: “I knew Pearl had the job, but I couldn’t tell anyone and she couldn’t tell anyone.

“It was only because I had worked in that theatre previously and all the front of house staff knew me, so they said ‘Peter, you must go backstage’.”

Peter went on to remark that his night out turned into a test of his acting abilities, the BBC reported.
“So, that was a great performance of mine pretending that I didn’t know Pearl,” Peter added.

His comments come just days after Pearl was announced as Doctor Who’s latest companion during the FA Cup semi-final on Saturday.
She replaces Jenna Coleman, whose character Clara Oswald left the show last year.

The 10th series of Doctor Who will air in 2017.