Driver arrested over fatal hit-run in Melbourne's south-east after initially thinking he hit a pothole

A man has been arrested over a fatal hit-run in Melbourne after he initially thought he had hit a pothole.

Emergency services were called to Frankston-Flinders Rd near Highland Dr about 5.30am on Tuesday to reports a woman had been hit by a car.

The pedestrian, an 83-year-old Frankston South woman, sadly died at the scene.

A witness who saw the hit-run was first on scene and immediately called for help.

“It would appear to us at the moment this lady’s been laying on the road or very close to and has been hit by or struck and run over by the car,” Major Collision Investigation Unit Detective Mark Amos said.

“This morning we’ve got a family that’s lost a mother, a wife, a grandmother and someone is going to try and give them some answers.”

7NEWS understands the driver contacted police after hearing what had happened on the news, telling officers he thought he had hit a pothole.

The 55-year-old was arrested at his scaffolding business in Seaford, about 15 minutes from where the accident occurred.

It is understood that when police first arrived to arrest the driver, he was visibly distressed at what had happened and told detectives they had his full cooperation.