A vehicle involved in a horrific crash which killed four people south of Hamilton is alleged to have been travelling in excess of 150km/h at the time.

The trial involving Dylan Cossey and Stephen John Jones began in the High Court at Hamilton after the crash that killed young friends: Hamilton woman Hannah Leis Strickett-Craze, 24, Paul De Silva, 20, and Lance Robinson, 28, both of Te Awamutu, and Jason McCormick Ross, 19, of Stratford.

Plumber Matthew Scheepers of Hamilton was seriously injured.

The crash happened on Ohaupo Rd, at the intersection of Ingram Rd, outside Hamilton Airport, on June 24, 2016 when a northbound Nissan Skyline collided with Scheepers' southbound van.

The pair originally faced charges of either encouraging unnecessary speed leading to the injuries to Scheepers and the deaths of Ross, Robinson, De Silva and Strickett-Craze, or in Cossey's case, operating a motor vehicle on a road causing death. However they were upgraded to four charges of manslaughter last year.

The pair also face a charge of operating a motor vehicle in a race or unnecessary exhibition of speed causing injury to Scheepers and failing to stop.

Jones faces an additional charge of attempting to pervert the course of justice at Hamilton on June 28, 2016.

The trial, before Justice Anne Hinton, is set down for two weeks and involves 21 witnesses.

Opening the crown case, prosecutor Duncan McWilliam told the jury neither Cossey or Jones knew any of the deceased and simply engaged in a race after coming across each other while driving on State Highway 3, near the Wild Thyme Cafe.

Cossey was estimated to have been driving in excess of 150km/h when the crash occurred.

Jones' extra charge relates to him editing a video showing how fast Cossey was going at the time of the crash.

McWilliam said Jones and Cossey has picked up a friend who was having a birthday and then stopped at a bottle store in Kihikihi.

At the same time, Robinson in his Nissan Skyline had stopped at a Z service station in Te Awamutu.

Another vehicle, recognised an occupant in Robinson's car but was unable to engage in conversation.

Both vehicles left the station while Cossey's vehicle pulled out onto SH3 just north of Te Awamutu town.

It was near there where they came across the Nissan Skyline being driven by Robinson.

The cars began to increase speed by the time they had reached the Wild Thyme Cafe and proceeded to pass two vehicles.

The occupants of those cars and a third which will be passed north of Ohaupo, will give evidence about how their car felt as the two vehicles allegedly sped past.

The occupants of a home near the crash scene will also give evidence about hearing two loud vehicles and looking out the window.

At the time, Scheepers was heading south as Robinson lost control of his car after passing Cossey's car and crashing into his Toyota Hiace van.

The crown alleges Cossey then sped through the crash scene, failing to stop and offer any assistance.

Jones is alleged to have filmed the crash, which he is also accused of later deleting.

Police claim he originally had 38 seconds of footage but cut it down to 11 seconds the morning of his interview with officers.

Defence counsel Philip Morgan QC will issue a short opening submission.