The Odessa File was the bestseller written after The Day of the Jackal by Frederick Forsyth.
In the book, Odessa are an organisation formed to protect ex-SS members and to try to implement a final solution of their own via a rocket attack on Israel. The book is set in late 1963 and 1964 and involves some real-life people including The Butcher of Riga Eduard Roschmann and the Nazi hunter Simon Wiesenthal.
The suicide of an elderly German Jew in Hamburg leads to a journalist, Peter Miller, being given a diary by a police contact. Miller reads the book and is determined to find Roschmann, although the real reason for his interest is only revealed late in the book. Miller has a voluptuous girlfriend and a sports car he adores, which is almost the downfall of him. Miller races around Germany, flies to London, and visits Vienna in pursuit of leads to discovering where Roschmann is. He succeeds in finding Roschmann, but the ending is a surprise.
Interestingly, Wiesenthal helped Forsyth with his research in order to force the real-life Roschmann out into the open. Sure enough, the publicity worked and Roschmann was eventually identified and denounced by a man who had just watched The Odessa File at the cinema.