Mara and Jordan play superhero siblings Sue and Johnny Storm in the latest Marvel flick, but some movie fans have taken aim at film bosses for casting an African-American male for the lead role.

Among the critics is Atlanta, Georgia DJ Jason Bailey, who asked the stars about the casting on his Rock 100.5 Morning Show, saying, "From what I've seen, you're brother and sister."

Jordan simply concurred with the statement, to which Bailey said, "Am I missing something?"

The actor firmly responded, "No," but the DJ kept pushing and added, "You're white and you're black. How does that happen?"

Jordan replied, "They could be raised as brother and sister. There's a whole bunch of family dynamics that could be without the obvious adoption."

Meanwhile, Bailey's co-host Southside Steve, real name Steven J. Rickman, turned his attention to Mara, who recently chopped off her longer locks in favour of a pixie cut.

Steve said, "You're way, way hot. Why'd you cut the hair? Your hair was beautiful."

The House of Cards actress quipped, "This is a great interview... I cut my hair for a movie I just did... I'm an actress. I have to be a chameleon."

The shock jocks were soon escorted out of the room, but Bailey defended their questions after received an uproar from critics online.

Bailey says in a statement to Buzzfeed: "Look, not a huge fan of these controlled 5-7 minute interview junkets they run in the first place but I was curious about the brother and sister thing... The other Fantastic Four franchises explain the relationship so I figured with this new hipster version they'd have some different back story.

"My partner's (Southside Steve) conversation about Kate's hair is something that came up while Michael B. Jordan took a phone call so I think they were kind of just going back forth in a playful way... People should be appreciative when they get complimented. Those that are upset on Twitter I guess don't get enough of them. Who knows?"