Olivia Munn says "nothing" could have prepared her for the emotional shock of seeing her body after she underwent a double mastectomy.

The 34-year-old actress had been due to shoot a sci-fi film in Germany this time last year, but instead had to go under the knife after oncologists discovered she was suffering stage one invasive cancer in both her breasts.

Olivia told People about having her double mastectomy within 30 days of her life saving diagnosis: "There's so much information and you're making these huge decisions for the rest of your life.