A man who allegedly fled to the NT after allegedly being involved in a fatal crash two years ago while high on drugs in WA has been arrested on an interstate warrant, NT Police said.

Detectives with the Major Crash Investigation Unit arrested the 36-year-old man this morning at his Rosebery residence.

NT Police said he will be charged with dangerous driving causing death and driving while impaired by drugs and will face court in Western Australia.

The man will appear first at the Darwin Local Court today.

Detective Senior Sergeant Brendan Lindner said Western Australian Major Crash detectives will go to Darwin to make an application to the NT Courts to extradite the man back to Perth, where he will appear before the WA Courts to face the charges.

NT Police did not give further details on how many were killed during the 2019 road incident.

They also did not explain why it took two years to locate the man and carry out the arrest.