Melissa McCarthy fights puppet in hot tub for The Happytime Murders

US actress Melissa McCarthy has risen to become one of Hollywood's top stars, with a series of comic performances in films like Bridesmaids, Spy, The Heat and the Ghostbusters reboot.

Her latest work is one of her most daring yet.

Directed by Brian Henson - son of Muppets creator Jim Henson - M18 black comedy The Happytime Murders, which opens here tomorrow, is set in a world where humans and puppets co-exist.

McCarthy plays detective Connie Edwards, a Los Angeles cop who must reluctantly team up with her old partner, puppet private eye Phil Phillips (Bill Barretta), when a killer begins to murder the former members of a TV show.

Here, the 48-year-old talks about the challenges of acting with puppets (even in a hot tub), why she does not really have a dirty sense of humour and collaborating with her husband, actor-director Ben Falcone for the fourth time.

What did the Henson family's work mean to you growing up? Were you a big Muppets fan?

Well, I think everybody was. It is a rare thing to have something that is that universally loved. That was exciting to bring all that knowledge and history into something different. This is definitely not the Muppets. It is not a movie for kids. But to have that lineage working on it was pretty exciting.

What was the biggest challenge on the film? Was it integrating with the puppets?

Working with them was incredibly easy because all the puppeteers are so phenomenal.

Initially I thought, "Will it be really difficult to connect and just keep eye contact with a puppet?"

I kept thinking, "I better keep looking at the puppeteer, not the puppet."

And everyone said, "You won't do that. You'll only look at the puppet."

I was like, "Mmm, I don't know. I have a feeling I'm going to look for real eyes and some kind of emotion."

The first time I even met Bill Barretta, who does the voice of Phil and is the puppeteer behind him, I immediately looked at a puppet. They are so skilled at what they do, they just dissolve behind the puppet and you find yourself kind of insanely only talking to the puppet.

Even when we are not shooting, I still found myself chatting with the puppets for a few minutes and then I said, "I'm so sorry, I realise you're a human holding a puppet."

But the technical difficulties of making a puppet movie were surprising. So many things have to change. The construction and building of the sets, how you move across a room when there are three people manning one puppet that can't be seen, it becomes incredibly technically difficult.

How was it to shoot the hot tub fight with Phil where you bite him in the crotch?

Short. Very wet. Kinda dangerous. It was a very tiny hot tub - it is made for small puppets. So it was Bill and I in there, plus Bill holding Phil, but it was really funny.

I just thought, "You can't be that effective in water. You can only be so tough."

I love that even though you are trying really hard to fight, you are slipping, falling down, and I just thought it was a ridiculous way to have a fist fight.

At times I didn't know if I was punching Bill or Phil. I didn't know who was hitting what. I think that was a real standout for me.

The film has plenty of X-rated jokes. Where did your dirty sense of humour come from?

Well, it is funny. I don't think I have a dirty sense of humour at all. I sometimes think I'm prudish for certain comedy.

I think I play characters that have sworn a lot, and that is always relative to the character.

I have played characters that would never ever say a cuss word or anything inappropriate. And then I just happened to play, especially in the beginning, really hard-boiled, sweary, grizzled people. If the character warrants it, you have to go with it.

You are filming action comedy Super Intelligence in Atlanta, directed by your husband Ben Falcone. This is your fourth collaboration with him, after Tammy (2014), The Boss (2016) and Life Of The Party (2018). How do you work so well together?

We just have a similar vision and we probably have different strengths.

We met doing improv, performing together and writing together, and it is part of why we became such good friends so fast. We really loved working with each other.

He has a really calm, wonderful ability to stay on track and see the big picture whereas I get myopic and am really obsessive with the little details.

He will always say, "But it still has to fit in this world."

So as a director and also a performer, he sees the details but he is amazing at keeping the whole thing in the correct tone and making sure that A still links to B and links to C.

It is really a great balance.