Luc Besson has said that Scarlett Johansson is very different to the actress that people think they know from magazines, but she was the perfect choice for his film Lucy.

The director and writer cast the Captain America actress in the starring role of his sci-fi thriller, which sees her as a drug mule who gains superhuman powers when a large quantity of a drug she is carrying is planted in her body and bursts.

He said: "She's brilliant and she's a good actress first, you can tell. She was able to go from Sophia Coppola to Woody Allen to the play she did in Broadway that I've seen twice. She's a good actress, she has a lot of capacity.

"Then we met and she has a lot of questions about the subject, and she's looking at you in the eyes for hours. She's a serious girl, she's a serious worker. She's very far from the image that we have on the cover of magazines where she's all gorgeous and the most beautiful woman in the world, and she is, that's one aspect.

"But the one I love is the tough cookie who comes with no make-up and asks questions."

Luc added that he was still amazed he had been working in the film industry for so long.

Asked what his proudest moment was, he replied: "A proudest moment, I honestly don't know. Sometimes what I'm surprised about is that I'm still there. I started at 17 years old and I'm still there.

"My biggest fear after my first film was, 'I wish I can do another one, a second one.' And my fear after the second one was, 'Let me do a third one, please.' I can't believe I'm still there making films and that I have the ability to and people still let me do films and go to see them so thank you to everyone, because I'm very happy to still be there."

Lucy is released in cinemas on August 22.