The High Court in London refused to grant the BBC an injunction blocking the publication by HarperCollins of an autobiography of former Formula Three driver Ben Collins.
The book, called The Man In The White Suit, claims Mr Collins is the mystery driver on the BBC Two show.
The Stig is famous for his racing overalls and dark-visored helmet. His identity has long been a closely-guarded secret on Top Gear - one of the BBC's most popular shows in the UK and around the world.
Last week, HarperCollins said it would "vigorously defend" its right to publish the book, adding it was "disappointed that the BBC has chosen to spend licence fee payers' money to suppress this book".
However Top Gear executive producer Andy Wilman attacked the publisher, writing on the Top Gear website that the BBC had a right to protect Stig's anonymity "from a bunch of chancers" who were "hoping to cash in on it".
Source: BBC