So, Long John Silver, where did the leg go?

The mysteries of Robert Louis Stevenson's greatest work have enthralled readers for more than a century. And yet, at the end of Treasure Island, many questions remain unanswered. How did Long John Silver lose his leg? Why is Pugh blind? And, most importantly, where is the treasure?

Now, after 125 years, there is at least the prospect of some answers. A book claiming to be the prequel to Stevenson's classic novel is to be released next week.

The author John Drake, a former biochemist and freelance TV producer, has spent years studying Treasure Island line by line, together with books and essays on 18th-century shipping and piracy.

The book, Flint & Silver, is the first in a scheduled series of six, snapped up last year by Harper Collins. Mr Drake is currently negotiating with a US publishing house for the American rights.

Speaking this weekend from New York, the British author said he first became fond of the book when he read it as a child. He rekindled his love for the work when he became a full-time author in 1999. "Recently, when I was able to become a full-time writer, I re-read the book – just for fun, and then – and this is the real inspiration for writing the book – I realised that Treasure Island reads like a sequel," said Mr Drake. "It's full of questions. Such as: Where did Long John get the parrot? Who was the black woman that he married and who is referred to disparagingly in the book?"

Stevenson was 30 years old when he started to write Treasure Island at Braemar in the Scottish Highlands in 1881. The story was originally serialised in the children's magazine Young Folks between 1881 and 1882 under the title "The Sea Cook", although it failed to make much of an impact. It was not until it was published as a book in 1883 that it took off, selling widely and garnering critical praise.

One of the biggest myths that Mr Drake wanted to dispel was that pirates buried their treasure: "This is nonsense. Pirates never bury their treasure. There is no known proven example of pirates burying their treasure on an island. Pirates led short, violent lives and when they got money, they went to an island and spent it on booze and girls and when they'd run out they went and got some more."

He also claims to have located the actual island that inspired the book. But, like the author, he refuses to divulge its whereabouts: "I'm never going to reveal the location of the island. But there's a lot of information in the original book, so if you read it carefully you can take a pretty good guess.

"Forgive me if I keep it a secret, but I can tell you it's very hot ..."

Many authors have tried to find it and candidates have ranged from Unst Island in the Shetlands to Norman Island in the British Virgins.

Unlike Stevenson, who wrote Treasure Island for his stepson Lloyd Osbourne, Mr Drake's book is aimed at an adult audience. Billed as containing "sex, violence and swashbuckling adventure", it has several new characters. "I don't write books without women," Mr Drake said. "So my books are not for children."