Image Entertainment has snapped up all U.S. distribution rights to U.K. indie “The Riddle,” which successfully world preemed as a DVD given away free with the Sept. 16 issue of Blighty’s Mail on Sunday newspaper.

The offbeat London-set detective thriller, starring Derek Jacobi, Vanessa Redgrave and Vinnie Jones, boosted the Mail’s circulation from its usual 2.3 million to 2.6 million, and the giveaway was a groundbreaking move for movie distribution.”It was fascinating watching the response from different parts of the industry (to the giveaway),” “Riddle” writer-producer-director Brendan Foley told Daily Variety.

“New or different distribution channels can clearly work alongside existing ones, if the right people are involved. Where a few dinosaurs saw only a threat, the smarter cookies saw an opportunity. We are still getting calls from producers and distributors from all over the place, both about the movie and the deal itself,” Foley added.

“The innovative and successful U.K. release certainly grabbed our attention. We plan on a second quarter 2008 release in the U.S.,” said Image Entertainment VP of acquisitions J. Beck.

Sales agent Hollywood Classics/Altadena Films has sold Australian DVD rights to the “The Riddle” to 21st Century Pictures Australia. No deal for U.K. theatrical or DVD has yet been inked.

Foley is finishing post-production on “Bog Bodies,” an Irish horror spoof, again starring ex-soccer player Jones alongside Jason Barry and Nora-Jane Noone.

“The Riddle” unspoiled Sunday at the Austin Film Festival and closes the Nantes British Film Fest in Gaul in December.

The Mail decided to try giving away a new film after successfully bowing Prince CD “Planet Earth” in the same way.