James Gunn's 'The Suicide Squad' took big inspiration from "1970s war caper" movies.

Producer Peter Safran has opened up on the direction the 'Guardians of the Galaxy' filmmaker took the comic book blockbuster, which is a continuation but not a direct reboot or sequel to David Ayer's 2016 original'.

Safran told Total Film magazine: "This is the Suicide Squad through the vision of James Gunn. It's very much 'The Dirty Dozen' meets 'Guardians of the Galaxy'.

"The reason that the studio was so keen to do this with James is to get that great things he brings to the table - the comedy, the heart, the action, the look.

"He had a very specific vision for the film, which he pitched from day one as a 1970s war caper movie."

Gunn agreed with the asessment, and admitted he loved the idea of taking a group of "sad-sack supervillain soldiers" and dropping them into an epic environment.

He added: "I love 'The Dirty Dozen', I always have. I've always loved tales of redemption of bad characters who become good, or find some hint of goodness i themselves.

"I loved [writer] John Ostranger's original run on 'Suicide Squad' [comics in the 1980s].

"The basic elements of that squad were what excited me, that it was a group of B-rate supervillains who were used as human fodder in black-ops missions by the US government.

"The idea of putting these sad-sack supervillain soldiers in this huge war film was exciting to me."

And part of this was making sure to have "big sets" rather than relying too heavily on CGI.

Gunn explained: "I always end up spending money on CG sets when I could have built sets and saved money, so I was like, 'Let's just build the biggest sets Warner Bros has ever had!' I just liked the practical feel."