The team behind “Black Panther,” the film featuring the first black superhero to appear in mainstream comics, is facing allegations by a British-Liberian artist that her work was used without permission in Kendrick Lamar’s just-released music video for “All the Stars,” a song from the movie’s soundtrack.

On Saturday, Christopher Robinson, a lawyer for the artist Lina Iris Viktor, sent a letter to Mr. Lamar’s mentor and label head, Anthony Tiffith at Top Dawg Entertainment, alleging a copyright violation of the 24-karat gold, patterned artworks in her series of paintings “Constellations.” Ms. Viktor had been contacted twice by the film’s creators for permission to feature her work, the letter says, but she decided not to participate.

“The infringement of Ms. Viktor’s rights is willful and egregious,” the letter says, adding that the artist is willing “to discuss a resolution of all her claims, consisting at a minimum of a public apology for the unauthorized use and a license fee.”

In a telephone interview, Ms. Viktor said, “Why would they do this? It’s an ethical issue, because what the whole film purports is that it’s about black empowerment, African excellence — that’s the whole concept of the story. And at the same time they’re stealing from African artists.”