A U.S. district judge ruled that key plot elements in the Broadway musical adaptation of the Fox's 1997 animated film Anastasia share noticeable similarities with both the 1952 Broadway play and 1956 film that preceded it.

The April 2 ruling is the latest development in the ongoing copyright lawsuit filed by Etienne de Becdelievre, heir of playwright Marcelle Maurette, who also wrote a 1952 play based on the life of the Grand Duchess Anastasia Nikolaevna of Russia.

Anastasia’s producers, named in the suit alongside Tony-winning book writer Terrence McNally, initially moved for summary judgment, stating that the two works were not substantially similar. U.S. District Court Judge Alvin K. Hellerstein denied the motion, ruling that the similarities between McNally’s book and Maurette’s play were substantial enough to head to trial.

The parties are due back for a status conference on April 13 to determine whether or not further discovery into the case is needed. If none is needed, a trial date will be set.

Read: JUDGE DENIES MOTION TO DISMISS ANASTASIA PLAGIARISM SUIT

De Becdelievre’s lawsuit states that while Maurette’s original play was licensed by Fox for the 1956 film adaptation of Anastasia, the agreement stipulated that the playwright and translator Guy Bolton retained “rights to the production on the spoken stage.” Fox later extended motion picture rights to the play in 1963 and again 1993, the latter resulting in the 1997 animated film musical. A retroactive license was obtained in 1998 for Anastasia on Ice. In each case, according to De Becdelievre’s suit, the licenses did not include rights to present Maurette’s play onstage.

While Anastasia is at heart inspired by historical fact, Maurette’s heirs state that key plot developments were the sole creation of the late playwright. Cited are a reunion scene between Anastasia and the Dowager Empress, as well as character traits specific to the original play.