Four years after Bridesmaids, Melissa McCarthy continues to break the Hollywood mould.

Susan Griffin meets a woman on a mission...

Melissa McCarthy's known for her physical comedy, but filming for her latest movie was by far the most physically demanding yet.

"Running, jumping, falling, I've cracked my head, had cuts and bruises. At the end of the day, I looked like I'd fallen down an elevator shaft.

"But I wore those wounds and thrown discs with a bit of pride," says the 44-year-old, who's reunited with director Paul Feig - who also helmed 2011's Bridesmaids, the hit comedy that really put McCarthy on the map - for new big-screen flick Spy.

Although inspired by the Bond films, this isn't a spoof of the genre, she's keen to point out.

"When Paul and I first spoke about it, I said if she stays smart and the action stays dangerous and real, then we've really got something," notes the actress, who plays Susan Cooper, an unassuming, desk-bound CIA analyst.

Susan boasts the skills of a field agent, but lacks the self-esteem to actually do the job, and so she remains in a basement office, serving as the eyes and ears for the narcissistic Bradley Fine, played by Jude Law, a man who remains oblivious to her blatant adoration.

"Jude was delightful, he's such a lovely, sweet guy, it was really fun," says the Illinois-born actress, who's reportedly lost 40 pounds and is looking a lot more glamorous than her often dowdy characters, in a flowing maxi-dress and bright red lips.

"But I think that's what Paul does so well. He knows how to put people together and somehow the chemistry is going to be just right."

The cast also includes fellow Bridesmaids alumna Rose Byrne as Rayna Boyanov, the snobbish, big-haired daughter of a recently deceased arms dealer, Miranda Hart as Susan's best friend and colleague Nancy, and Jason Statham as field agent Rick Ford, a man who makes up for in confidence what he lacks in actual competence.

It's a chance to see the action star in a new light, and McCarthy notes, "I think he had a great time doing it".

"He's so incredibly funny. He made me break the most, just because he would get so intense and so serious," she adds of co-star Statham. "It's like when your parents are yelling at you when you're a teenager and you start laughing at them."

When Fine falls off the grid, and Ford's identity is compromised, Susan musters the nerve to abandon her desk, and volunteers to go deep undercover, infiltrate a criminal gang and thwart an arms deal.

"I think people are going to be amazed by the level of action. It's slick, fast and dangerous," remarks McCarthy, who took on as many of the stunts as she was allowed.

"It works for the character because she's 10 years out of practice," she explains. "She was skilled and trained but hasn't been practising in the field, so it made sense. I wasn't going to be an amazing martial arts person, but that's OK, because Susan isn't either!"

Action aside, McCarthy admits one of the great attractions was the chance to wear different wigs and costumes, as Susan takes on different guises in a fruitless attempt to remain anonymous.

"I love to create characters from the hair down," says the star, who has two daughters with her actor/writer husband Ben Falcone, who often makes cameos in her films.

"I always thought I was going to design women's clothing, probably since grade school," she adds. "I went to college and was always very focused on it."

But then she moved to New York, became involved in the stand-up scene and thought, 'Uh-oh, I'm going to go a different way'.

McCarthy, who was a main stage member of the comedy-improv sketch group Groundlings for nine years after moving to LA, also appeared in numerous stage productions before making her first TV appearance alongside her cousin, Jenny McCarthy, in 1997.

Small film roles followed, and then in 2000, she was cast as the clumsy Sookie St. James in Gilmore Girls, the much-loved US series that ran until 2007.

For the next three years, she continued acting in films and TV, including her debut in sitcom Mike & Molly, which has earned her an Emmy Award and was recently recommissioned for a sixth series, before Feig cast her as the ballsy Megan in Bridesmaids.

Her performance garnered Academy Award and Bafta nominations, and the female-focused film has been credited with challenging the male-dominated industry.

"I think it's fantastic and hope to see more variety, more diversity and more projects with more women in them, and especially challenging, flawed women that are interesting to watch," says McCarthy.

"I want to see movies about real women that I love, even if they're crazy and flawed. The more we have of that, the better."

In recent years, the actress has appeared in This Is 40, St. Vincent, Identity Thief and Tammy, and in a couple of weeks will reunite once again with Feig, with whom she also worked on 2013's The Heat alongside Sandra Bullock, to start shooting the Ghostbusters reboot, which will boast female leads this time round. "I've latched onto him like a barnacle," she says with a laugh.

Later this year, she's also returning to her fashion roots and releasing a clothing line.

"I always had clients throughout my 20s who I made clothes for, and I've always sewn and made things, so to get to be able to do the acting and the clothing? I feel like him in some sort of dream," reveals McCarthy, who recently received a star on the Hollywood Walk Of Fame.

"I'm probably in a fever dream right now and I just don't know it. That's the problem. I'm going to wake up and go, 'I was having the greatest time'!"