Joss Whedon was concerned that The Avengers might turn into a "sausagefest."

The 47-year-old director cast Scarlett Johansson in the superhero movie - which sees her reprise her role of Natasha Romanoff / Black Widow from Iron Man 2 - to avoid the film being dominated by its male stars Robert Downey Jr., Chris Evans, Chris Hemsworth and Mark Ruffalo.

"Joss said to me, 'I want to do everything I can to keep this from being,' in his words, 'a sausagefest.' I said, 'That's disgusting, but okay,'" she told Empire.

Scarlett was also keen to ensure her alter-ego - who can be seen battling villains in a skin-tight catsuit in the movie - was not portrayed as a "love interest."

"I knew that I didn't want to play a love interest. That's not who Widow is. I think Joss understood the importance of having a female perspective. He's a very sensitive guy. He works really well with women. He obviously can write for them! He loves strong and independent women and he's got a certain understanding of and an appreciation for, women who take charge of the situation, of themselves so it was clear to me that the character would not be underwritten."