The rumor in the movie casting world today (September 12, 2014) is that Robert Downey Jr has signed on to play Leonardo da Vinci in the Assassin's Creed movie. The story was originally posted up on Moviepilot, but has since been removed. It is now being widely discussed on Reddit.

Robert Downey JrRumor has it that Robert Downey Jr has signed up for 'Assassin's Creed' [Getty/Jonathan Leibson]

"Huge Assassin's Creed movie news just dropped recently and it seems like Iron Man Aka Tony Stark Aka Robert Downey Jr is reportedly joining the Assassin's Creed movie cast as Leonardo Da Vinci," read the story before it was taken down.

Michael Fassbender remains attached to the movie as the lead star, though the Irish-German actor has previously said that while the team are looking to the games for inspiration, they're keen to mix it up and introduce original plotlines. 

More: Robert Downey Jr: "There are no plans for Iron Man 4"

Justin Kurzel is presumably still attached to the project as director and Fassbender spoke about what the filmmaker would bring to the project.

Michael FassbenderMichael Fassbender will play the lead in Assassin's Creed [Getty/Dimitrios Kambouris]

"I just think that there's one thing Justin should be doing, and that's directing. I know that from working with him on Macbeth. He's just fantastic in terms of his vision. Adam, the DP that he works with, is amazing. They've got a great shorthand -- that's essential. He's fantastic with actors and each department. He's a real heavyweight."

Downey Jr certainly has time to work on the project, given he recently wrapped The Avengers: Age of Ultron and went on record as saying there are no plans for Iron Man 4. His latest movie The Judge, with Robert Duvall, got a decent reception after opening the Toronto Film Festival earlier this month.

More: check out our Michael Fassbender pictures

The Assassin's Creed movie is set to hit screens on May 22, 2016 - which isn't actually that far away now, is it?