Alan Dean Foster was the ghostwriter of a novelization of the original film, titled Star Wars: From the Adventures of Luke Skywalker and credited to Star Wars creator and director George Lucas. He also wrote the first installment’s original sequel, Splinter of The Mind’s Eye, as well as the novelization of 2015’s Star Wars: The Force Awakens and two other stories set in the Star Wars universe. Foster says royalties for the early books stopped coming after Disney bought Lucasfilm in 2012.

“When you purchased Lucasfilm you acquired the rights to some books I wrote,” Foster wrote in a letter addressed to “Mickey,” which was published Wednesday by the Science Fiction and Fantasy Writers of America (SFWA). “STAR WARS, the novelization of the very first film. SPLINTER OF THE MIND’S EYE, the first sequel novel. You owe me royalties on these books. You stopped paying them.”

Foster also accused Disney of not paying him royalties that he is owed for the novelizations of three Alien films, a franchise the company owns after purchasing 20th Century Fox in 2019.

“All these books are all still very much in print,” wrote Foster. “They still earn money. For you. When one company buys another, they acquire its liabilities as well as its assets. You’re certainly reaping the benefits of the assets. I’d very much like my miniscule (though it’s not small to me) share.”

“My wife has serious medical issues and in 2016 I was diagnosed with an advanced form of cancer,” he continued. “We could use the money. Not charity: just what I’m owed… Maybe someone in the right position just hasn’t received the word, though after all these months of ignored requests and queries, that’s hard to countenance.”

Foster added that he had refused an alleged demand from Disney to sign a non-disclosure agreement (NDA) before even discussing the matter. However, a Disney spokesperson told Newsweek that the company had not corresponded with Foster since March, with discussions focused on the Alien franchise only. The spokesperson said the company did not hear back from Foster after asking for an email confidentiality request concerning discussions, rather than a formal NDA.

SFWA President Mary Robinette Kowal said that Disney’s reasoning for not paying Foster is that they bought the rights to the intellectual property of the sci-fi franchises, but not the accompanying contractual obligations, asserting that “they have the right to publish work, but are not obligated to pay the writer no matter what the contract says.”

Kowal warned that allowing Disney to continue to ignore contract obligations would be a threat to all writers and could “fundamentally alter the way copyright and contracts operate in the United States.” She urged Foster’s fans to “let Disney know” if they feel that “a writer’s work has value.”

On Monday, Disney said it had reestablished communications with Foster and expects to meet with him to discuss the issue soon.

Update, 11/23 5:20 p.m.: This article has been updated to include new information and details from a Disney spokesperson.