Liam Neeson spent the whole time filming The Naked Gun unsure if it was "working" for him.

The Taken actor portrays Lt. Frank Drebin Jr. in director Akiva Schaffer's upcoming reboot of the classic action comedy series and while he thought his co-stars were "very funny", Liam wasn't quite sure if he had the comedy skills to pull off the role.

He told Entertainment Weekly: "During the whole shoot -- I'm being very honest -- I still did not know, when we wrapped at the end of each working day, whether it was working for me.

"Pamela [Anderson], Paul [Walter Hauser], Danny [Huston], everybody else, I thought, were very funny.

"I just couldn't put a verdict on myself, on my own performance. I'd always ask Akiva, 'Are you sure it's working?' That continued from day one till we finished."

Cruella star Paul was surprised by how "nervous" Liam was about the project.

He said: "He was acting really humble and nervous to do comedy.

"We all knew he could do it, but he kept just being like, 'I really hope I'm doing this right.'"

Producer Seth MacFarlane had the "wild idea" to cast Liam in the lead role after working with him on Ted 2, and believes he is the "only" actor alive who could follow in the footsteps of the franchise's late former lead, Leslie Nielsen.

He said: "Liam Neeson is probably the only actor alive in the 21st century who could do what Leslie Nielsen did, largely because that kind of actor is not something that we're really generating a lot of in Hollywood anymore.

"[He's] larger than life on screen and yet so honest, two things that don't always mesh, but he's really able to be that kind of an on-camera powerhouse."

Seth's faith in Liam made him believe he could tackle the role.

Liam said: "I thought, Can I pull this off? The fact that it was Seth's idea, I thought, Well, maybe he sees something in me."

The original Frank Drebin was originally created by brothers David and Jerry Zucker and Jim Abrahams for the short-lived comedy series Police Squad!, and Seth insisted it was key not to cast a comedian as the cop.

He said: "One of the cardinal rules for the Zucker brothers was that you don't cast comedians.

"You cast serious, dramatic actors, preferably with a ton of gravitas, which Liam has in bountiful levels."

Despite Liam's reservations, his co-star Pamela insisted the 73-year-old star had no problem with any of the slapstick elements of the film.

She said: "He really is a silly guy. He acts like a silly little boy sometimes."