The film is based on the book Vengeance:
The True Story of an Israeli Counter-Terrorist Team by Canadian journalist George Jonas, which in turn was based on the story of Yuval Aviv, who has claimed to have once been a Mossad agent. In the book, Aviv's story is told through a protagonist called "Avner".
Journalist Yossi Melman of the Israeli newspaper Ha'aretz has said that the book is "strewn with mistakes", adding that after a lawsuit identified Aviv as Avner, "investigative reports about him revealed that he represented himself as a Mossad agent even though he had never worked in the Mossad and certainly had not participated in operations to kill those involved in the athletes' murder.
