It’s here that Australia’s most successful hip-hop act is finalising their new single.

The question I’ve asked J Emz - does OneFour have gang links? - has long stalked the group.

To fans, the rappers are pioneers: five Sāmoan-Australians from one of Sydney’s poorest postcodes who have used their explosive sound to give voice to millions of marginalised young people.

But to police, OneFour is a threat to community safety, to be managed and contained.

For years, they have blocked the group from performing at home by arguing their music incites violence - triggering a complex debate about art and censorship.