The follow-up to 2009's Avatar is currently scheduled for release in December 2014, with a third instalment set to arrive a year later.
However, Jon Landau, a producer on the film, has claimed that the sequel is "four years away", according to Bleeding Cool.
Asked for a release date clarification, Landau later said: "It's in that window - 14, 15... yeah."
Director James Cameron said earlier this year that the upcoming Avatar sequels will not round out a trilogy, insisting the two films will be able to stand alone.
Cameron previously announced that production for the two highly-anticipated sequels to Avatar will take place at a studio in Manhattan Beach, California.
In October, Avatar star Sam Worthington revealed that the plot for Avatar 2 is "monumental".
Watch the Avatar trailer below: