One of the things that intrigued me most when first I came to Kingston was the sight of parakeets, green-feathered and glamorous, swooping down on our garden.

Soon I found they were swooping on the rest of the royal borough as well, and wondered why.

Everyone gave the same answer: the birds had been imported for the filming of The African Queen at Shepperton Studios in the 1950s, escaped when the film was finished and the ones we see now are their descendants.

That is still the accepted theory today, but it is wrong.

For one thing, no parakeets were imported for this film. For another it was made at Isleworth Studios, not Shepperton.

The man who has exploded this long cherished myth is Kingston University graduate Ed Harris in Britain’s Forgotten Film Factory, The Story of Isleworth Film Studios, just published by Amberley and costing £18.99.

This is truly an extraordinary tale – extraordinary that a studio that was once the most technically advanced of its kind in Europe, and where some of the best examples of British cinema were made, should be virtually forgotten.

Extraordinary, too, that its Oscar-winning triumph, The African Queen, has been wrongly credited to Shepperton Studios.

Cinema historians and reviewers thought the film had been shot there.

So did the executives at Shepperton, who boasted that the River Ash that flows behind their premises had doubled for the lethal Congolese waters in The African Queen and who, says Ed Harris, were “devastated” when he revealed the truth.

A third extraordinary factor is George Berthold (Bertie) Samuelson, the pioneer who founded Isleworth studios – and did so much to give cinema a key role in British cultural life – has also been airbrushed from public memory.

The story begins in 1914 when Mr Samuelson set up Samuelson Film Manufacturing Company and bought the Worton Hall estate, on the Twickenham/Isleworth borders, for an astonishing £200.

Worton Hall was a country mansion, built in 1783. When Mr Samuelson bought it, its original 13 acres had been reduced to nine, comprising terraces, lawns, paddocks, orchards, vineries, a farm and woodland which, he thought, would provide a good variety of outdoor filming options. Meanwhile he set about converting the mansion and constructing an ultra-modern glass studio in the grounds.

Though Worton Hall Cinematograph Studio officially opened on July 1, 1914, work was already well under way on its first production: a film dramatisation of Sir Arthur Conan Doyle’s A Study in Scarlet.

This was Britain’s first Sherlock Holmes feature film and, according to the Bioscope magazine at the time, “would go far indeed towards placing this youthful producing house in the front rank of English manufacturers”.

Alas, the film of A Study in Scarlet has, in Harris’s words, “gone the way of the millions of silent nitrate stock long since lost to history” and only its publicity campaign sheets survive.

Worton Hall’s ups, downs and unique achievements over the next 38 years have been meticulously researched by Harris, whose book reveals a wealth of previously unknown, or totally forgotten, facts.

He tells how Mr Bertie Samuelson eventually lost Worton Hall in the general malaise among British film makers following the First World War, and said the golden age of film production at Isleworth began when movie mogul, Alexander Korda, took over Worton Hall, and in 1935 built the largest film stage in Britain for Things to Come, Saunders of the River and other titles.

Flushed with success, Korda moved to costly new premises at Denham, whereupon Worton Hall was taken on by Douglas Fairbanks Jr, who had hopes of establishing a British Hollywood there.

But, Harris said: “With fewer than 20 film companies active out of the 640 registered in England since 1925, the Fairbanks flirtation proved as brief as it was abortive.”

Meanwhile Korda’s backers were bitterly regretting his extravagant Denham dream and after World War II – during which Worton Hall was requisitioned for war work – he returned to Isleworth as head of his new British Lion Film Corporation.

There was a brief resurgence at the old mansion. There Emric Pressburger and Robert Donat made their directorial debut, Richard Burton appeared in his first film and it hosted the production of classics such as The Third Man and The Small Back Room.

Its last hurrah was The African Queen, still regarded as one of the best films ever, and popularly believed to have been made at Shepperton Studios.

How did Ed Harris, a former film researcher who gained his local history degree at Kingston University and who now lives in Whitton, write such a richly detailed book in only nine months?

He said: "I put a letter in the Bectu trade union journal, Stage Screen and Radio, asking for memories of the Worton Hall studio and was overjoyed to hear from Bertie Samuelson’s two sons, Sidney and David, who are both now in their 80s.

"They were delighted at the thought of their father’s achievements being recognised and they gave me huge quantities of archive."