Speed is likely to have been a factor in Monday night's fatal crash on Dunedin's Southern Motorway, police say.

The death brought the Easter road toll to four.

A police spokeswoman on Monday night said the sole occupant of the vehicle in the crash had been critically injured.

In an update yesterday morning, police confirmed the driver had died at the scene.

Acting Sergeant Rhys Davidson said speed appeared to have been a contributing factor.

The serious crash unit attended and inquiries were ongoing, he said.

The crash happened near the Main South Rd off-ramp, close to the Lookout Point Fire Station, about 9.10pm.

The road was closed overnight while the scene was examined.

On Friday, 27-year-old Tajinder Singh died in a two-car collision near Queenstown.

Forty-eight-year-old milk tanker driver Daryl Paul Hutt, of Timaru, died in a single-vehicle crash in South Canterbury on Saturday.

Another person was killed in a fleeing driver incident in Auckland on Thursday.

Last Easter weekend nine people died on the country's roads.

This year's Easter holiday period ran from Thursday until 6am yesterday.