Nightcrawler has unveiled it's darkest trailer yet starring Jake Gyllenhaal.

The psychological thriller sees the 33-year-old as Lou Bloom, a man struggling to find work who discovers the world of Los Angeles crime reporting.

Directed by Dan Gilroy, thefilm follows Gyllenhaal as he teams up with a local TV news veteran (Rene Russo) and an unusual group to find the next big story.

However Lou's shady methods land him in hot water, as he finds himself involved in a murder case that that could have detrimental consequences on his life.

Sporting a much thinner frame than usual, Gyllenhaal told Us Weekly of his 20lb weight loss: "I knew that [Lou] was literally and figuratively hungry, [so I got into the] mode where I was always a bit hungry."

Also starring Rene Russo, Bill Paxton and Riz Ahmed,Nightcrawler is out in the UK on October 17.