Charlie Cox felt starstruck when he met Robert De Niro for the first time.

The 40-year-old actor starred alongside the Hollywood icon in the 2007 fantasy movie 'Stardust', and Charlie still considers it to be one of the best experiences of his career.

Asked about his best on-set experience, Charlie replied: "I'd been cast in 'Stardust', I was 23, and I was going to Pinewood every few days for a fitting or a rehearsal.

"Once I was waiting by the studio, smoking, and a car pulled up and Robert De Niro got out. I hadn't know what we were going to rehearse that day, but it was our fencing stunt. That was a moment of, 'Holy s***, I'm about to work with ... Bob.'"

Charlie now feels a "responsibility" to set the tone whenever he's cast in a lead role.

He told Total Film magazine: "I think there's a responsibility for you to set a tone.

"I've been on sets where the lead actor has not fully embraced that, and it can lead to strange feelings on set."

Charlie has enjoyed success in the film and TV industries during his career.

Despite this, he's still retained some of his long-standing superstitions.

The actor - who starred alongside Eddie Redmayne and Felicity Jones in 'The Theory of Everything' in 2014 - shared: "On stage, I annoyingly buy into some of those things, like you never say the name of the Scottish play, and I try not to whistle. I don't buy into it - I just don't want to risk it!"