There's no truth to the rumor that the movie Spencer, which centers on Princess Diana, is casting a non-British actor to play Prince William. The producers clarified the audition process amid reports that British citizens do not need to try for the role due to Brexit.

According to The Guardian, the Spencer casting notice indicated that actors who plan on auditioning for the role of 11-year-old Prince William must be British-European passport holders. The film's casting director, Amy Hubbard, shared on Twitter that the passport consideration is based on new Brexit rules come Jan. 1, 2021.

Hubbard explained that this stipulation was necessary for the production to qualify for grants, tax breaks and eligibility criteria in awards and film festivals. Apparently, a significant role like Prince William should have an actor with a passport that matches the movie's financiers.

The film will start principal photography in Germany in early 2021. Brexit will take effect on Dec. 31, 2020.

But Spencer producer Paul Webster told Deadline that they have been in the process of meeting British actors. He clarified that they are not necessarily looking for a foreigner to play Prince William but if the actor has an Irish passport then it's still "well and good."

Webster confirmed that they do need to cast European actors for funding requirements. Still, the film is generally a co-production between British and European companies, and he doesn't anticipate any issue with a British cast member in Germany. He said that their production has no connection to Brexit.

Meanwhile, Stewart said that she feels quite protective of Princess Diana ahead of working in the movie. The actress said that she was really young when Prince William's mother died. However, she's aware that the royal was loved, and she recalled scenes where people laid a sea of flowers at the gates of Buckingham Palace after news of her tragic accident came through.

Stewart said that she's been working on a dialect coach to do justice to Princess Diana. She has also read her biographies and books to prepare for filming.

Pablo Larraín will helm the movie from a script penned by Steven Knight. Spencer will cover the year Princess Diana spent Christmas with the royal family in Sandringham in the early 1990s. There, she resolved to close her chapter with Prince Charles despite the Queen's insistence that they cannot divorce.

It remains to be seen if critics will appreciate Stewart's portrayal and the movie's story, especially after criticisms of The Crown, another production about the royal family. Spencer has no release date so far.