Crowe (centre) has narrated a film about the gang's Abberton brothers

Bra Boys will be based on a real-life, Sydney-based gang of the same name.

Crowe recently narrated a documentary about the group, also called Bra Boys, which is currently number four at the Australian box office.

The Gladiator actor's only directing experience comes from documentaries about his band, 30 Odd Foot Of Grunts.

Based in the Sydney district of Maroubra, the Bra Boys are a tattooed and often violent gang, renowned for their anti-authoritarian, anti-social behaviour.

Murder case

Crowe's film, like the documentary, will focus on founder members the Abberton brothers.

The siblings hit the headlines in 2003 when Jai Abberton was accused of murder.

Although he was acquitted in 2005, his brother Koby - a professional surfer - was given a suspended sentence for perverting the course of justice by withholding information about the killing.

Variety reports that the drama is being scripted by Stuart Beattie, who wrote the screenplay for Collateral and Pirates of the Caribbean.

It is not known whether Crowe will appear in the film.