The duo was rumoured to be planning a new movie, loosely based on the 1992 Whitney Houston and Kevin Costner hit.
Aussie actor Jackman was expected to play a New York police detective hired to guard a spoiled teen heiress - played by Cyrus - after she receives a kidnap threat.
But the X-Men star has no plans to get in the firing line - he won't be appearing in the film.
A spokesperson for the actor says the reports are "totally false".