Northern Territory Police responded to a fatal vehicle crash in Kakadu overnight.

At around 3am, police received reports of a single vehicle crash along the Arnhem Highway, 10km west of the South Alligator River.

The vehicle was carrying six people, with a 31-year-old man declared deceased at the scene.

Five people were conveyed to the local clinic in Jabiru with non-life-threatening injuries.

Detectives from the Major Crash Investigation Unit are investigating the circumstances of the crash.