Frank Marshall says it's unlikely there will be a 'Indiana Jones 5'.
Though there has been speculation there will be a follow-up to 'Kingdom of the Crystal Skull', producer Frank says there are no plans for the archaeologist - played by Harrison Ford - to have a "last hurrah".
He said: "I say, for me, ['Kingdom of the Crystal Skull' is] the last hurrah. I know that yes, we talk about it, but there's no idea, there's no MacGuffin."
Last December George Lucas - who created the franchise alongside Steven Spielberg - revealed he had "told Steven about the story" but he hadn't found a plot yet.
However, George announced his retirement from filmmaking in May, and Frank confirmed that the 'Star Wars' creator is not keen to make another 'Indiana Jones' film.
Frank - who is married to Kathleen Kennedy, who is set to take the reins at Lucas's studio Lucasfilm - said: "Yeah, no, he isn't [hungry to do another 'Indiana Jones'], and he's obviously passing the baton to my wife."
The last movie in the franchise, 'Indiana Jones and the Kingdom of the Crystal Skull' was released in 2008.