The heartbreaking pleas of a family desperately seeking answers about their husband and brother's death two years ago aired on Police Ten 7 tonight.

The mysterious road crash near Te Aute, Hawke's Bay tragically claimed the life of Taranaki's Hemi Rapaea, 62, who had been hitchhiking north of Dannevirke and given a ride.

Sergeant Cory Ubels, officer in charge of the Serious Crash Unit in Hawke's Bay, hopes viewers will be able to help identify the driver of a silver Ford Fairmont that crashed about 3.15am on March 10, 2016, north of Te Aute College on SH2.

Speaking from the scene of the mysterious crash in last night's episode, Ubels urged those who knew about the events that occurred in the early hours of that morning to come forward.

"The two people that know what happened here, the chances are the burden on them has been pretty high, he's essentially killed someone in a car crash."

Hemi's wife, Mirianna tearfully retold the moment she found out her husband had died.

"I couldn't believe it... They didn't ring for help, they just took off, so I am very angry about that."

"If it was their loved one ... I'm sure they would want answers and closure. I think they have to come forward and own up to it," she said.

Hemi's sister, Bernadette said it had taken a "dramatic toll" on their family, with his children needing to know what happened to their dad.

"We don't know what happened, all we know is that he was hitchhiking and we get a call that he has been killed... Please just help out, let somebody know,"

The car he was a passenger in veered off the road into bushes, flipped on its roof and then landed back on the road.

The driver fled.

A truck driver came across the crashed car and called emergency services.

Ubels says evidence suggests two vehicles were travelling in convoy.

"The evidence suggests that the driver got into another vehicle that he had been travelling in convoy with at the time and has left the scene. The driver of the car and the driver of the second car travelling in convoy could have assisted Hemi and chances are that had he been assisted at the time Hemi would be alive," Sergeant Ubels said.

"We don't know why he's done that. He's left someone to die on the side of the road as did the driver of the second car but unfortunately it's left a family devastated."

"This is a 62 year-old man whose got 8 children 26 mokopuna his family don't have the answers they need to be able to put this to rest."

Police spoken to two people they thought could have been with the car when it crashed but no one has been arrested.

Extensive searches in the area, including the use of a drone fitted with cameras, failed to find the driver.

Sergeant Cory Ubels filming with Police Ten 7 host Detective Sergeant Rob Lemoto at the scene of the mystery fatal crash. (Photo/Supplied )

"This has been a long and complex investigation for which Mr Rapaea's grieving whanau need answers," Ubels said.

"I'm hoping that with the passage of time, people who have information about the crash and the driver's identity, will be prompted to come forward and tell us what they know."

Police previously said it was possible the driver had fallen asleep at the wheel, because no evasive action seemed to have been taken.

The car appeared to have rolled into a roadside ditch, and it seemed no other vehicle was involved.

Police Ten 7 host Detective Sergeant Rob Lemoto said "the callous decisions of a driver that night have left the family devastated and they need answers".

"It's been two years of hurt for the family of Hemi Rapaea and it was time they were given some closure. I have no doubt that the two who fled the scene have talked to others about the events that unfolded that morning."

• Police Ten 7 screened last night at 7.30pm on TVNZ 2 and is available now on the Police Ten 7 and Eastern District Police's Facebook pages.