UPDATE: After attending a NY press screening, Moviefone can confirm that Jack Kirby's name is listed in the end credits as a co-creator. Previously, we referred to Kirby's omission from promotional materials of the upcoming film. Original story appears below.

On May 4, the hugely anticipated adaptation of Marvel Comics' premiere superhero team, "The Avengers," hits theaters. But what many movie fans might not realize is that a nasty battle regarding ownership rights is currently going on behind the scenes.

Most people know Stan Lee as the father of the Marvel Universe, but his efforts creating Spider-Man, Iron Man and the X-Men were not accomplished single-handedly. When the Avengers made their comic book debut in September 1963, Lee shared co-creator credit on the book with artist Jack Kirby. The prolific illustrator, who passed away in 1994, is also credited as the co-creator of characters Captain America, Thor, Iron Man, the Incredible Hulk, Nick Fury and big-screen bad guy Loki.

However, the artist nicknamed "The King" left Marvel in 1970, and for the rest of his life, he had a tempestuous relationship with the company, as well as Lee, fighting over credits, royalties and ownership of his artwork. It's a complicated case brought on by vague legal terms and changing copyright laws in the U.S. (changes ironically lobbied heavily for by the Avengers' new owners, Disney). Just last year, Kirby's estate lost a legal bid for the copyrights to the characters he helped bring to life.

Not surprisingly, Jack Kirby's co-creator credit appears nowhere in the promotion of "The Avengers." His fans have expressed outrage over the way his contributions to the movie's very existence are being swept under the rug. Stephen Bissette (co-creator of "Constantine," and noted "Swamp Thing artist) called for a boycott of Marvel comics and merchandise, while James Sturm, co-founder of the Center for Cartoon Studies, also published an essay explaining his decision to boycott the movie. Many fans have followed suit, arguing that while Disney and Marvel have no legal obligation to acknowledge Kirby, their actions are completely lacking in ethics.

During an interview to promote both "The Avengers" and his new documentary "With Great Power: The Stan Lee Story," Moviefone asked Stan Lee himself about his take on the Kirby controversy. His response is below. (The full Stan Lee interview will run next week.)

Fans of Jack Kirby are concerned that his name appears nowhere on the credits of "The Avengers." What's your take on their concern?
I don't know how to answer that because in what way would his name appear?

His name isn't mentioned anywhere in the film production as a co-creator.
Well it's mentioned in every comic book; it says "By Stan Lee and Jack Kirby."

But it doesn't appear for the film itself; and his fans feel he should get that recognition, with the movie exposing his work to a whole new audience.
I know, but you're talking to the wrong guy because I have nothing to do with the credits on the movies. I'm credited as one of the executive producers because that's in my contract. But Jack was not an executive producer. So I don't know what he'd be credited as. Again I know nothing about that, I have nothing to do with the movie's credits. You'd have to talk to whoever is the producer of the movie. Is there anything you want to ask me about the documentary because I thought that's what I was supposed to be talking about.

I will, but I have one last question on the subject. As an executive producer on "The Avengers," what advice would you have for a young comic creator that's trying to navigate this new world of movie adaptations?
The way it works is if you make a good comic book that would make a good movie, and some movie producer sees it, he'd want to buy the rights to the comic book. One thing you might want to do is if you have a comic book that is that good, is try to get an agent. Try to bring the book up to an agency like CAA or William Morris. It's always easier if an agent presents it, then just the person.