John Lennon's sons and widow, Yoko Ono, are suing the filmmakers of "Expelled: No Intelligence Allowed" for using the song "Imagine" in the documentary without permission.

Ono, her son Sean Ono Lennon, and Julian Lennon, John Lennon's son from his first marriage, along with privately held publisher EMI Blackwood Music Inc, filed suit in U.S. District Court in Manhattan seeking to bar the filmmakers and their distributors from continuing to use "Imagine" in the movie.

The suit is against the film's producers and distributors, Premise Media Corporation, C&S Production LP and Rocky Mountain Pictures. The plaintiffs are also seeking unspecified damages.

The documentary, which features Ben Stein, an actor, comedian and former speechwriter for President Richard Nixon, looks at alleged discrimination against scientists and teachers who support so-called intelligent design as an alternative to Darwin's theory of evolution.

The producers cited the fair use doctrine, which allows the use of copyrighted materials for the purposes of commentary and criticism.

"We are disappointed therefore that Yoko Ono and others have decided to challenge our free speech right to comment on the song 'Imagine' in our documentary film," they said in a statement.