When movie fans stream into cinemas this weekend to watch the latest big screen outing of Spider-Man in the animated Across the Spider-Verse, they will be adding to box office takings that have already hit $500m.

It is the most recent instalment for the multibillion-dollar juggernaut as the superheroes created more than six decades ago by Marvel Comics continue to take the world by storm.

And ever since Marvel was launched with the first issue of Fantastic Four in 1961, its founder Stan Lee has been presented as the supremo orchestrating what would become a global phenomenon. He was editor, art director and credited with writing the adventures of the superpowered family, followed by Spider-Man, the Hulk, Iron Man, Thor and many more.

But a new Disney+ documentary, Stan Lee, which uses archive footage and sound interviews to tell the story of Lee and Marvel’s meteoric rise, has reignited the anger of those who feel they have been written out of the story.

In a row that began before Lee died, his chief artistic collaborators, Jack Kirby and Steve Ditko, always claimed they had far more of a hand in the comics than the illustrations they were credited for.

Last week, after the release of the documentary, the family of Kirby, who died in 1994, said Lee had “the fortunate circumstance to have access to the corporate megaphone and media” and made himself “the voice of Marvel” – overshadowing the parts other people played.

Kirby’s son Neal told the Observer: “If you were to look at a list and timeline of Marvel’s characters from 1960 through 1966, the period in which the vast majority of Marvel’s main characters were created, you will see Lee’s name as a co-creator on every character, with the exception of the Silver Surfer, solely created by my father. Are we to assume Lee had a hand in creating every Marvel character?” Are we to assume that it was never the other co-creator that walked into Lee’s office and said, ‘Stan, I have a great idea for a character!’?”

The families of both Kirby and Ditko – who died a few months before Lee in 2018 – have been calling for more formal recognition for their part in creating the characters, especially now that Marvel is owned by Disney.

In September 2021, Ditko’s family filed a copyright termination notice with the US courts demanding rights to the characters they say Ditko created be handed to the family by Disney. The action has not yet been resolved.

Broadcaster Jonathan Ross has an encyclopedic knowledge of comics, and fronted a 2007 documentary in which he went in search of the reclusive Steve Ditko.

Ross says one thing cannot be denied: Lee’s huge contribution to the cultural landscape. “Without Stan Lee there would be no Marvel Comics, no Marvel Cinematic Universe,” he told the Observer.

“However, if you were to make a list of the people involved at the beginning of Marvel Comics in creative importance, Lee would come third, after Kirby and Ditko.”

Ross says Kirby in particular had a deep interest in mythology and literature, feeding into his work on Thor and the Jekyll and Hyde-inspired Hulk. Ditko is widely regarded to have come up with the idea of Spider-Man – and Doctor Strange is said to be entirely his creation.

“What Stan did was add the soap opera elements to these stories,” says Ross. “And that made them really popular not just among kids but among students and older readers. But he told the stories so many times about how he invented these characters that I think he started to believe them.”

In the 1960s, says Ross, when Kirby and Ditko were paid, their cheques carried a disclaimer saying that if they cashed it, they surrendered all rights to their work.

Ross says: “Many people are calling for the company to step up and correct the dubious business practices of the time.

The vast profits generated through the comics and films today would not exist without these people, so would it be so bad for a company as big as Disney to give them even a small slice of the money earned from their work?”

Is the situation any different now? Mark Millar is a Scottish writer who worked for both Marvel and its rival DC in the 1990s. For the former, he created with artist Bryan Hitch the series The Ultimates, which was heavily borrowed from for the first Avengers movie.

For Millar, his generation of comics creators went in “with their eyes open”. He says: “We knew that if we were working on characters owned by a company, we would never have any claim on them. It’s like if a decorator comes into your house. It’s their work and it looks great, but they don’t own your house!

“For people who came on board at the same time as me writing for Marvel was satisfying a childhood dream, but it also gave us an audience so we could create our own comics.”

The 1980s saw the rise of creator-owned comics, not controlled by big publishers such as Marvel, with artists and writers retaining their rights. Millar did this with his hit Kick-Ass, which spawned two movies and led him to set up a publishing company he sold in 2017 to Netflix.

“We had opportunities that they didn’t in the 1960s,” says Millar. “And people had no idea how important and valuable these franchises were going to be.

“It’s a shame, though, that these arguments arise, because to my mind Lee and his artists were just as important as each other in the creation of these comics. Stan Lee and Jack Kirby, they’re basically the Lennon and McCartney of comics.”

Both Marvel and the representatives of Lee’s family were approached for comment.