Brad Pitt and Darren Aronofsky are working on new adventure thriller 'The Tiger'.

The movie - based on a non-fiction book yet to be released by John Vaillant - has been optioned by Focus Features, with Brad potentially taking a leading role.

The story - which is being scripted by Guillermo Arriaga - tells the tale of human developers in Siberia who are tracked and hunted by an "almost" supernaturally-powerful tiger, Variety reports.

Guillermo said: "This is the first time I have adapted a screenplay, since I have previously only written original screenplays.

"I chose to adapt this story, first, because I have a profound love for the outdoors and the intense tension between man and nature which the book reflects; and, second, because of the great privilege of working with such accomplished filmmakers as Darren Aronofsky, Brad Pitt, and James Schamus."

Guillermo and Brad previously worked together on drama movie 'Babel' and both dropped out of 'The Fighter' - which now stars Christian Bale and Mark Wahlberg.

The novel 'The Tiger: A True Story of Vengeance and Survival' is due for publication in August.