LaBeouf in Disturbia.

...now that they’re getting close to production, I’ve heard a persistent rumor, a new version of that old familiar. The thing is, I’m hearing this from some pretty reliable places.
So here we go again.

Shia LaBeouf will play the son of Indiana Jones.

The thing is, we know Spielberg loves La Beouf right now. Disturbia became a pet project for The Beard, and it evidently came out well. Transformers is a big deal for the company, and a lot of the weight of that falls squarely on the shoulders of Shia. So as much as I pray that there’s no Indy Jr., I’m starting to think that this may in fact be true.

One of these reliable places Moriarty refers to could be a story Latino Review posted a couple weeks ago. But they were forced to take it down after it was online for only a few minutes... until yesterday:

I had a chance to speak to Shia LaBeouf a few weeks ago here in NYC and I asked him what he was working on next now that he's rapped Transformers. Shia replied something like this: “I can't really say because.... put it this way, I'm trying to work something out to be in the next Steven Spielberg movie.”

When I pressed him if it was Lincoln, Shia laughed it off. He just gave me a look saying “NO WAY!" Then when I asked him point blank if it was Indy IV. He put on a devilish smile and said “I'm trying to work it out. I don't want to loose the role to another actor so I really can't say much but it will be announced very soon.”

A few days later our sources said that Steven loves Shia and that he's up for one of two roles, either Indy's son or a faithful sidekick.

Even though Aint It Cool News and Latino Review seem to be certain that Shia will be in Indy 4, it's best to take this as a rumor till an official source confirms it. Spielberg's Amblin Entertainment has informed me today that "As of now, no casting deals have been made for Indy 4".

The rumor that Indy will have a son or daughter in the upcoming fourth film has reappeared many times over the past 10 years. Some of these rumors even linked Natalie Portman as Indy's daughter.
And many years before David Koepp delivered the final approved script, Harrison Ford once commented "Hey, there's only one son in these movies and I'll always be Sean Connery's little boy!". But that was in 2002 already...

Trivia: In some scenes of The Adventures of Young Indiana Jones TV-series, the 93 year old Indiana Jones had a daughter. But all those scenes got cut out of the most recent video release in 1999.

A big thanks to Maxime Ferland, Jared Barrett, Eric Roth, Tony Santore, Chris Ziegler and Brett Hopkins for informing me.