Michelle Monaghan secretly battled skin cancer.

The 'Machine Gun Preacher' actress had a mole on her leg investigated after being urged to by husband Peter White during a vacation in Australia and is "grateful" she sought medical advice when she did.

She said: "A few years ago I had a mole on the back of my calf, and [my husband Peter White] was adamant that I get it checked.

"In Australia, they're very aware of skin cancer. I finally went and it was skin cancer. I had quite the chunk taken out of my leg. I'm so grateful he noticed it. He has a keen eye - [I wonder] what other imperfections he's noticing!"

Michelle - who has two-year-old daughter Willow with her husband of six years - is now very cancer aware and "regrets" the fact she used to be a smoker, though she hopes quitting the deadly habit has minimised damage she caused to herself.

The 35-year-old beauty told the new issue of Health magazine: "I smoked for almost 10 years. I really regret that. Thankfully, I came out on The Other Side. I hope my lungs are repairing themselves now."