UPDATED 6.27PM: The holiday weekend road toll now stands at three.

The Serious Crash Unit is investigating a fatal crash near Wallacetown in Southland, where one person has died.

Police have confirmed the collision occurred on Underwood-Linds Bridge Road just after three this afternoon.

A fire communications spokesman said they were called to the scene to clean up after a collision involving two vehicles, one a motorcycle.

Cordons are in place, State Highway 99 is closed and motorists are advised to avoid the area.

Steel Road and Underwood-Linds Bridge Road are also partially closed.

Earlier today, police said 79-year-old Te Rauoriwa Daphne Pomare died in Wellington Hospital overnight from injuries arising from a head-on crash on State Highway 1 south of Paekakariki late yesterday morning.

Earlier yesterday, one person died when their car hit a median strip then a truck on the Southern Motorway near Pokeno.

Five people died last year during the Labour Weekend holiday period which ends at 6am tomorrow morning.