NT Police are investigating a fatal crash between a car and a motorbike in Darwin's rural area on Tuesday night.
The motorcyclist, 54, suffered fatal injuries in the accident on the Stuart Highway outside the Noonamah Tavern, about 40 kilometres south of Darwin, around 7:45pm.
NT Police watch commander Neil Mellon said, "the car was travelling in a northerly direction, executing a right-hand turn into the Noonamah precinct, and it turned into the path of an oncoming motorcycle travelling south".
"The impact was serious," he told ABC Radio Darwin on Wednesday morning.
"As a result, I'm sad to report that the middle-aged rider of the motorcycle was declared deceased at the scene."
The driver of the car, a 47-year-old man, remained on the scene after the crash and helped police with their enquiries.
The man was breath tested and returned an alcohol reading under the legal limit, but tested positive for cannabis, NT Police said in a statement.
In a statement, detective senior sergeant Brendan Lindner said the driver was arrested for the purpose of obtaining a blood sample at hospital, and was released pending further investigation.
Traffic diversions were in place on the Stuart Highway until early Wednesday morning, but the road has since been reopened.
"Those involved, and the frontline staff that attended the incident, are being provided with ongoing support," Sergeant Mellon said.