Melissa McCarthy soon forgot she was working with puppets on the set of her new film The Happytime Murders.

The film tells the story of disgraced LAPD detective-turned-private eye puppet Phil Phillips as he investigates the murders of the puppet cast of an '80s children's TV show, who start getting picked off one by one.

Directed by Brian Henson, son of legendary puppeteer Jim Henson, Melissa plays Phil’s ex-partner Detective Connie Edwards, and the actress quickly got to grips with her non-human co-stars.

“What’s crazy is that I thought it was gonna be this whole tricky thing. I thought, ‘Okay, I guess it will be kinda like with a tennis ball, just ‘cause there’s no eye contact and they’re not looking at you’,” she said to Collider. “What happened, about 15 minutes in, was that I bumped into Phil and I was like, ‘Oh, I’m sorry, Phil.” And then, I was like, ‘Oh, okay, I’m nuts!’ We’ve had emotional scenes.”

Bill Barretta is the puppeteer behind Phil, and will be known to audiences through his work as Pepe the King Prawn and Swedish Chef from The Muppets.

Melissa credits her co-star with making Phil so believable to act opposite.

“Bill Barretta is a dreamboat,” she stated. “He’s so good. This is his grandfather – Phil. It’s such a personal, dreamy character, at the heart of it. His face can barely move and his eyes can barely move, but when Phil is upset, everybody feels it. That’s Bill Barretta being this weird wizard at what he does.”

The Happytime Murders hits cinemas in August (18).