Star Wars actor Mark Hamill has claimed it is "possible" that Luke Skywalker could turn to the dark side in the next chapter of the saga.

Speaking at Star Wars Celebration in Florida after the teaser trailer for The Last Jedi was released, the actor hinted that the iconic character could possibly go bad in the new film.

"It's possible, anything's possible," he said.

During the panel discussion he joked with fans, saying that he suffers from "short term memory loss" and said he "lost credibility with the public through social media because I lie all the time".

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"And I post an exclusive look at the Episode VIII trailer and it's a trailer on the back lot... It's like the boy who cried wolf, nobody believes me," he added.

At the same event it was revealed that the late Carrie Fisher had a hand in re-writing the script for The Last Jedi.

"Carrie is remarkable in the movie," Lucasfilm head Kathleen Kennedy stated.

"What Rian [Johnson] wrote, and the performance she ended up giving; I think you guys will find that an amazing tribute to her talent."

Director Johnson added, "I love her so much. I just adore her. I connected with her first and foremost as a writer. She was an incredible writer, with an incredible mind."

The follow-up chapter to 2015's The Force Awakens sees the return of Daisy Ridley's Rey, John Boyega's Finn, Adam Driver's Kylo Ren, and Oscar Isaac's Poe Dameron.

The trailer also finally gave Hamill's Luke Skywalker some dialogue, following his silent appearance in The Force Awakens.

Star Wars: The Last Jedi is due to be in cinemas on 15 December.