Julie-Anne McPhail, who looks like Mr Falconio's then girlfriend Joanne Lees, travelled through outback South Australia and Western Australia with Bradley John Murdoch in a two vehicle convoy.
Ms McPhail said she shared a campsite with Murdoch on June 19, 2001, telling him of her plans to travel in a Kombi van through the Barrow Creek area with a friend, News Limited reports today.
"I said to (Murdoch) I'd be going that way, that I'd be driving in a Kombi and that I couldn't wait to get up to Alice Springs and Barrow Creek - and that was where he was waiting (for Joanne Lees and Peter Falconio)," she said.
Almost four weeks later, on July 14, Peter Falconio was believed murdered near Barrow Creek and Joanne Lees made her famous escape.
"Apparently he saw them in a fast food outlet from a distance and everybody thinks I sound a bit English, so maybe there was something similar there that clicked in his mind," said Ms McPhail, who now lives in Queensland.
Ms McPhail was a witness in Murdoch's trial last year but was excluded from hearing the evidence of other witnesses.
She only realised this week how close she potentially came to tragedy when reading Ms Lee's book.