Peter Gallagher claims Whedon and co-writer/director Drew Goddard based their 2012 film on his 2007 book The Little White Trip: A Night in the Pines.

The author insists some of the characters' names in both the book and the film and the plot twists are similar and both feature five friends.

In his documents, obtained by TMZ.com, Gallagher claims there are 25 scenes in his book that are almost replicated in the movie.

He is seeking damages in excess of $10 million (GBP6.7 million).