Before the publication of The Afghan in August, Mr Forsyth gave fans the chance to bid for the right to have their names included in the book.
The on-line auction raised almost £100,000 for charity and the author has revealed the character of special forces officer, Captain Michael Linnett is actually named after a county man.
In an interview with German magazine, Der Spiegel, the author said: "I got about £100,000 for different charities.
"Captain Michael Linnett, the special forces officer in the race through the wilderness, is actually a businessman in Northamptonshire, for example."
The auction, which was held on the web-site eBay in 2005, offered the chance to bid for six different character names in the book.
But despite admitting the character of Captain Linnett is named after a Northamptonshire man, Mr Forsyth has not revealed any more details about who the man is or where exactly in the county he comes from.
His latest book follows the story of British special-ops soldier Mike Martin who is chosen to infiltrate Al Qaeda.
It follows a string of successful thrillers written by Mr Forsyth, beginning with the international bestseller The Day of the Jackal, which was published in 1971 and later turned into a film starring Edward Fox.
But despite his decision to auction off characters in his book over the internet, Mr Forsyth has also revealed his work has led to a mistrust of both the internet and mobile phones.
He said: "I don't own a cell phone and I don't own a computer either. I'm obviously much mocked for being such a dinosaur, but I have my reasons.
"With my typewriter I've never sent seven chapters into cyberspace and lost them.
"Secondly, try hacking into my typewriter. I also don't use the internet for searches, because frankly I don't trust it."
wayne.bontoft@northantsnews.co.uk