An internet publishing firm is taking legal action against comic book company Marvel, claiming part-ownership of superheroes such as Spider-Man.
Stan Lee created Spider-Man in 1962
Associated Press reported the case was filed in New York last week by Stan Lee Media, a company originally co-founded by Spider-Man creator Stan Lee.
Now under new ownership, the firm claims Lee signed away rights to his famous comic book creations in 1998.
Marvel deemed the legal action "without merit", while Lee called it "baseless".
"I do not support this action and believe the suit to be baseless," said a statement released on behalf of the 84-year-old Lee by Marvel.
Lee's comic book characters include the X-Men, the Incredible Hulk and the Fantastic Four.
Stan Lee Media, which has re-emerged from bankruptcy six years ago, claims Lee signed away his rights to the comic book characters in 1998 when the company launched, in exchange for a salary and company stock.
It claims the agreement entitles Stan Lee Media to a 50% cut of the profits made by Marvel from licensing comic book characters to the film industry.
The second sequel in the Spider-Man series opens in May
Earlier this year, Lee took legal action challenging the legitimacy of Stan Lee's Media current management, calling them "rogue opportunists".
Lee founded Stan Lee Media with Miami businessman Peter F Paul in 1998, in a bid to bring some of his comic book creations to the web.
Despite early success on the stock market, the company crashed losing millions in investment, and prompting the firm to file for bankruptcy in 2001.
In 2005, Mr Paul pleaded guilty to improperly manipulating the company's stock price. Lee was never implicated in the scandal.
After his own legal battle with Marvel in 2005, which saw a judge uphold Lee's demand for 10% of Marvel's profits from the Spider-Man films, Lee is currently Publisher Emeritus at Marvel.
Blockbuster sequel Spider-Man 3, starring Tobey Maguire and Kirsten Dunst, is released in May this year.