Robert Pattinson tried to sneak away from the 'Tenet' set to audition for 'The Batman'

Speaking to The Irish Times newspaper, Robert said: "It's funny because Chris is so secretive about everything to do with his movies. And then I had to be really secretive about Batman stuff. So I had to lie to Chris about having to go for a screen test – I said I had a family emergency. And as soon as I said 'it's a family emergency' he said: 'You're doing the Batman audition, aren't you?'"

However, Robert admitted that working on 'Tenet' ultimately helped his audition as he had gotten extremely fit from trying to keep up with co-star and former football star John David Washington on set.

He explained: "When I'm running on screen I'm generally paired with John David who is an ex-NFL player so it was the most unfair thing in the world. The maximum workout I do most of the time is a casual stroll. John David can run all day long. It was good that I ended up being pretty fit. But definitely, at the beginning, there were days I just could not walk afterwards."

Meanwhile, Robert admitted he wasn’t sure what 'Tenet' was about during shooting.

He said: "When I first read it both Chris and [producer] Emma [Thomas] were saying: did you read this properly because everyone else took another two hours? And I said: Oh s***. Right up until the last week of the shoot, I was talking to John David and asking him some pretty fundamental questions about who my character was. And John David was like: 'Wait, you don't know this?' But it's complicated! You're not just being fed the story.

"You're trying to uncover the mystery at the same time as the characters in the movie are. A lot of the stuff in this movie is expositional world-building stuff and a dense story. And the script makes that accessible to a layman. And that's really difficult to get that balance of making it sound like natural dialogue and trying to get across information that you probably need a PhD to understand properly. And then you have to put it in the mouth of someone like me, who can barely add."