One person has died in hospital following the serious crash in Dairy Flat this morning, bringing the holiday road toll to eight.

Two vehicles were involved in the collision on Kahikatea Flat Rd.

Police had rushed to scene of the crash and advised motorists to avoid the area.

Shortly after the crash a local told the Herald the collision had occurred between a 6 wheeler tanker and a car that was coming out of a driveway.

The Serious Crash Unit was notified.

The fatality brings the holiday road toll to eight - double last year's toll.

Earlier today a person died following a two-vehicle crash in Pahiatua.

Police were notified of the crash on Nikau Rd at 4.58am.

Another person suffered serious injuries and has been taken to hospital.

The road remains closed and police have advised motorists to avoid the area.

Yesterday, two people were killed by a crash between a milk tanker and a motorcycle in Southland yesterday.

The crash occurred at the Oreti River Bridge on the Riverton-Wallacetown Highway about 1.30pm.

The man died at the scene while a woman died in hospital a short time later.

In a separate crash, the death of two promising young men on Boxing Day has had a ripple effect of grief across the West Auckland community.

Jack Heritage Jnr and Viliami Muru-Teutau, both 20, died after a crash on the Triangle Rd bridge that links Massey and Henderson.

Two others were taken to hospital.

Grieving dad Jack Heritage Snr told the Herald the family had been comforted by the sheer number of people who had visited them to pay their respects.

His "kind-hearted" son made friends with ease, Heritage said yesterday.

"I have been telling them; 'I wouldn't want your parents to go through what we are going through now'.

"It is so painful."

Muru-Teutau's family earlier released a statement describing the young dad as a naturally gifted sportsman who loved rugby.

He was a former NZ Māori under-18 player, who played for a New South Wales country team last year, before coming home to play in the Waitematā Rugby Club's premier team.

As a roofing apprentice, he was working hard towards completing his trade training to provide for his young family.

"Our world has been turned upside down and inside out," the family statement said.

"This is supposed to be a holiday season of festive happiness, and instead we are weeping and we are grieving."

The holiday road toll's first victims came on Christmas Day with the deaths of Terry Charleston, 34, and Rebecca McAlees, 24, after a single-vehicle crash in southeast Auckland.

Police confirmed speed is suspected to be a factor in the crash but categoric confirmation of what went wrong would only be given when the serious crash investigation was completed.

Charleston's brother Jason Ward spoke to the Herald urging drivers to slow down and take care on the road.

"Don't speed," Ward urged motorists. "If you are going to speed there is a race track [for that]."