Katherine Heigl and director Robert Luketic attended the European premiere of Killers in London's Leicester Square, but there was no sign of leading man Ashton Kutcher.

The actress wowed in a figure-hugging black dress by Victoria Beckham with grey and black high heels and wore her newly dark brown hair in curls. Katherine revealed that she had to stop herself getting carried away in a scene where she flirts with co-star Ashton.

"It felt a little like I was taking it a little seriously and blushing a lot and batting my eyelashes," said the former Grey's Anatomy star, 31.

Director Robert Luketic asked Ashton to bulk up for his role and said he was surprised to see how seriously the actor took his fitness regime.

Killers is out in UK cinemas on June 18.