Future Star Wars films aren't beholden to the post-Return of the Jedi Expanded Universe, Lucasfilm has revealed.

Rumours have been circulating that the upcoming movies will feature characters such as Han and Leia's twin children Jacen and Jaina Solo, Grand Admiral Thawn and Mara Jade Skywalker.

In a post on the Star Wars website, Lucasfilm describes the Expanded Universe (EU) as "anything in the Star Wars universe outside the scope of the movies or TV shows, such as books, comics, games, etc".

It also said: "While Lucasfilm always strived to keep the stories created for the EU consistent with our film and television content as well as internally consistent, George Lucas always made it clear that he was not beholden to the EU.

"In order to give maximum creative freedom to the filmmakers and also preserve an element of surprise and discovery for the audience, Star Wars Episodes VII-IX will not tell the same story told in the post-Return of the Jedi Expanded Universe."

Lucasfilm said that Expanded Universe content would appear in the new animated series Star Wars Rebels.

"While the universe that readers knew is changing, it is not being discarded.

"Creators of new Star Wars entertainment have full access to the rich content of the Expanded Universe. For example, elements of the EU are included in Star Wars Rebels.

"The Inquisitor, the Imperial Security Bureau, and Sienar Fleet Systems are story elements in the new animated series, and all these ideas find their origins in role-playing game material published in the 1980s."

Director JJ Abrams's Star Wars Episode VII will be released in December 2015, kick-starting a whole new slate of movies.

A new range of Star Wars books will be released by Disney this September.