Image caption British actor Martin Freeman stars in The Hobbit: An Unexpected Journey

The film studios behind The Hobbit films are suing low-budget company The Asylum for trademark infringement, over its new film Age of the Hobbits.

Warner Bros, New Line Cinema, MGM and The Hobbit producer Saul Zaentz want to stop them using the word Hobbit in the title of the "knockoff film".

They claim The Asylum is "free-riding" on the worldwide promotional campaign for Peter Jackson's forthcoming films.

The company is behind a string of "mockbusters" inspired by hit movies.

Producers of The Hobbit called it an "intentional and wilful attempt to trade on the popularity and goodwill" of both The Lord of the Rings and Hobbit films, and the JRR Tolkien novels they are based on.

Court papers obtained by The Hollywood Reporter have called Age of the Hobbits a "confusingly similar and misleading title".

The Hobbit: An Unexpected Journey is due in UK cinemas next month, the first in a new trilogy of prequels to The Lord of the Rings.

Producers want all infringing ad materials and packaging for The Asylum's film to be destroyed, adding that it could "divert customers and potential customers away from the Hobbit films".

The Asylum had already been threatened with legal action by the Hobbit studios and The Zaentz Co which controls trademark rights to the Tolkien book.

The protected phrase has been associated with Bilbo Baggins and his fellow Middle Earth creatures since the book was first published in 1937.

'Fair use'

Age of the Hobbits is due for DVD and online release on 11 December, three days before the US opening of the official Hobbit film.

The Asylum claims its movie is legally sound because its hobbits are not based on the Tolkien creations.

Before legal papers were officially filed the company said in a statement: "Age of the Hobbits is about the real-life human subspecies, Homo Floresiensis, discovered in 2003 in Indonesia, which have been uniformly referred to as 'Hobbits' in the scientific community."

It added that the term is therefore "protected under the legal doctrines of nominal and traditional fair use".

The Asylum also suggests that a Google search of hobbits and archaeology would return dozens of articles containing the term.

Some of their previous "mockbusters" include Transmorphers, based on Michael Bay's big budget movie Transformers, and The Da Vinci Treasure, which took its name from The Da Vinci Code, directed by Ron Howard and starring Tom Hanks.

Based on the story of a big blockbuster they are made at a fraction of the cost and are usually released straight-to-DVD.