A Superior Court order was filed Tuesday finding that Tyler Nelson knowingly violated the agreement that he signed when he was cast to appear in a scene of "Indiana Jones and the Kingdom of the Crystal Skull," said Lucasfilm Ltd. publicist Lynne Hale.
The agreement barred everyone involved in the film from publicly discussing it.
Terms of the settlement were not disclosed. An after-hours call to Nelson's talent agency was not immediately returned.
The fourth installment of the adventure series was directed by Steven Spielberg and stars Harrison Ford, Cate Blanchett and Shia LaBeouf. It is due out in theaters next May.
Tyler revealed plot details during an interview last month with his hometown newspaper, Oklahoma's Edmond Sun, Daily Variety reported. That story has been removed from the newspaper's Web site.
"We ask every cast and crew member to sign a confidentiality agreement because we want to protect the movie's thrills and surprises for audiences," said Lynn Bartsch, Lucasfilm's director of business affairs.
A spokesman for Spielberg said he didn't know whether Nelson's scenes would be cut from the movie.
Meanwhile, several photographs and computers being used for the film have been stolen, said Kristin Stark, spokeswoman for DreamWorks Pictures SKG.
The stolen items contained "confidential and proprietary materials" related to the movie, Stark said. She did not say when or where the theft occurred.
Stark said DreamWorks had asked for a criminal investigation. Officials from local law enforcement agencies could not immediately confirm they were investigating, the Los Angeles Times reported Wednesday.
Spielberg's spokesman Marvin Levy said the director was worried thieves may try to sell the materials.
"We want to warn the media that anything that is offered is stolen property," Levy said. "We know it is out there."