LOS ANGELES -- There could be a fifth Indiana Jones movie, and it would still feature Harrison Ford.

That's because producer George Lucas said Ford is Indy. Period.

Lucas said that Shia LaBeouf's character is not Indy, and if Indy isn't in it, Lucas said, "You'd have to call it 'Mutt Williams and the search for Elvis."'

In the latest film, "Indiana Jones and the Kingdom of the Crystal Skull," Karen Allen reprises her role of Indy's lover, Marion Ravenwood, from "Raiders of the Lost Ark," and LaBeouf plays Williams, Indy and Marion's love child.

To date, "Indiana Jones and the Kingdom of the Crystal Skull," has made nearly $315 million domestically and an additional $430 million overseas.

Lucas said that if there's going to be a fifth Indiana Jones movie, he has to come up with a good idea.

He said the series is "research-intensive." So, his staff is doing research now to see if there's "another object for him to chase."

Lucas is next producing the computer-animated "Star Wars: The Clone Wars," opening in theaters next week.