Laura Mulvey and Peter Wollen's visually accomplished and intellectually rigorous Riddles of the Sphinx (1977), featuring music by The Soft Machine’s Mike Ratledge, is one of the most important avant-garde films to have emerged from Britain during the 1970s.

Newly mastered to High Definition from materials preserved at the BFI National Archive, this extraordinary, era-defining work will be released by the BFI in a Dual Format Edition on 23 September 2013, presented with a wealth of essential bonus material.

The second collaboration between Mulvey and Wollen, both of whom are recognised as seminal figures in the field of film theory, Riddles of the Sphinx explores issues of female representation, the place of motherhood within society and the relationship between mother and daughter.

The film's ground-breaking electronic score, by The Soft Machine's Mike Ratledge, was composed on synthesisers which were developed in collaboration with Denys Irving (the man behind the mysterious and controversial 1970s band Lucifer).

Riddles of the Sphinx will be released on UK dual format (containing both DVD and Blu-ray) on 23rd September 2013 by the BFI at the RRP of £19.99.

Special features will include:

• Newly recorded feature-length audio commentary with laura Mulvey and academic Winfried Pauleit

• Laura Mulvey in Conversation (2013, 15 mins): the filmmaker and academic discusses Riddles of the Sphinx and other films

• Penthesilea: Queen of the Amazons (Peter Wollen and Laura Mulvey, 1974, 98 mins): trail-blazing avant garde film exploring the image of the Amazonian woman in myth and popular culture

• Illustrated booklet featuring new essays by Sophie Mayer, Laura Mulvey and Rob Young, and complete film credits

To re-launch the Essential Experiments strand that explores the rich history of artists' cinema, a pristine new digital print of Riddles of the Sphinx will be screened at the BFI Southbank, followed by a Q&A with laura Mulvey.

Tickets £9.50 (members), £11 (non-members), available from www.bfi.org.uk/whatson of the Box Office – Tel: 020 7928 3232, or in person.

Here is a short clip of the film: