Actor Sacha Baron Cohen will portray Mercury in the film about the rock star's life and career, while Tom Hooper is rumoured to be helming the project, reported Digital Spy.
Mercury had a long-term relationship with Austin in the early 1970s after being introduced by Queen's Brian May. The couple lived together for several years until Mercury had an affair with a male American record executive at Elektra Records.
However, the pair remained very close friends until the singer's death in 1991.
Cohen is said to be taking singing lessons in order to perform as Mercury in the currently-untitled film.