What's the most profitable movie of all time? The Sound of Music? ET? Lord of the Rings? Star Wars?

No. The answer is Deep Throat which - made for $22,000 with the intriguing premise that a clitoris has grown in the lead starlet's throat - grossed $600m.

Not bad for an X-rated movie that was banned in 23 states, attracted the ire of the Nixon administration and the director concedes wasn't actually very good.

Made on a shoestring in 1972, the movie was helmed by former beauty salon owner Gerard Damiano and starred suburban Long Island girl Linda Lovelace.

The film was structured - if that's not attributing it too much technical nous - around Lovelace's affinity for...how shall we put this gentle reader?...fellatio.

An overnight sensation in Times Square smuthouses, it inevitably came to the attention of City Hall whose moral guardians maintained "it strikes at the very core of our country. "

However, after earning some sort of respectability when labelled "porno chic" in the New York Times, well-heeled Upper East Side residents were making the trip downtown.

But the right had a secret weapon - federal prosecutor Larry Parrish, a lay preacher who proudly announces he would be happy to indict his mother if she was involved. "She wasn't," he assures us.

Next thing you know lead actor Harry Reems - who was paid $100 for his performance in - the judge's words - "this feast of carrion and squalor" - is facing five years in jail. Nixon's fall after Watergate gets him off the hook.

Much of this - particularly Lovelace's dire treatment at the hands of a controlling pimp/boyfriend - is well documented but the film-makers also turn up some gems.

Apparently New York mobsters cleaned up, extracting half the takings from distributors and cinema owners and poor old Jerry Damiano didn't make a red (or possibly blue) cent.

Probably the best decision was taken by the Lindsay Lovelace after her penniless mom died in a car crash in 2002. She turned down the lead in Deep Throat 7.

Tim Evans