Evangeline Lilly fears "purist" fans will hate her role in The Hobbit because her character didn't feature in the book and was invented solely for the fantasy film adaptation.
The Lost actress' Sylvan elf Tauriel was created especially for director Peter Jackson's upcoming Lord of the Rings prequel, based on JRR Tolkien's classic novel The Hobbit.
But Lilly admits she is terrified Tolkien devotees won't respond well when the movie epic is released next year.
"The Hobbit didn't include female characters at all. I can see why additional characters were needed to round out the story as an adaptation, especially female characters," she says.
"I am very concerned that people will watch and I'll be the black mark on the film. I know how adamant the purists are and I'm one of them."
Lilly was announced in June as the latest addition to the male-dominated cast, featuring Hugo Weaving, Benedict Cumberbatch, Martin Freeman and Lord of the Rings regulars Sir Ian McKellen, Elijah Wood and Orlando Bloom.