Northern Territory Police have arrested a male after a fatal hit and run in Alice Springs this morning.

Around 4:15am, police received a report that a 20-year-old male was lying unresponsive at the Larapinta Drive and Aldridge Street intersection.

Police believe the male was struck by a vehicle between 2:50am and 4:15am. The driver of the vehicle allegedly did not remain at the scene after the incident and did not inform emergency services.

The male suffered serious injuries and was conveyed to the Alice Springs Hospital where he was later declared deceased.

Prior to the incident, the male was in contact with police regarding a separate matter. Consequently, on behalf of the Northern Territory Coroner, the incident is now being investigated as a death in custody.

Just after 1:00pm, Northern Territory Police seized a black Ford Ranger and arrested a 32-year-old male in relation to the crash.

The male currently remains in police custody with the investigation into his involvement ongoing.

The Alice Springs Criminal Investigation Branch and the Major Crash Investigation Unit are investigating the crash and are urging anyone who witnessed the incident, particularly if you have dash-cam footage, to make contact on 131 444. Please quote reference number 2400029810.

You can also anonymously contact Crime Stoppers on 1800 333 000.