An air force helicopter hoists a car from the Mohaka River, in northern Hawke's Bay, after it plunged down a cliff, killing three Mongrel Mob gang members inside.

A father who had handed in his gang patch and tried to turn his life around is among three Hawke's Bay Mongrel Mob members killed when their car plunged 150 metres off a cliff into a river.

Their home town Wairoa was in "shock" at the deaths of the three men in the mysterious crash on Saturday.

One man died when the car crashed into the Mohaka River, in northern Hawke's Bay, and another managed to escape with minor injuries.

SUPPLIED Wairoa police issued this mug shot of gang member and dad Ronald Rigby in 1994. He was killed in a car crash this week. Recent court records show he had tried to turn his life around.

Two other bodies were later found trapped in the submerged wreckage.

Police named the trio as Terry Stone, 31, Ronald Rigby, 53, and Nathan Isaac, 29. All were members of the Mob's Wairoa chapter, who were driving to the gang's 50th anniversary celebrations in Hastings.

Detective Sergeant Brent Greville addressed speculation that tension between rival gangs could be implicated in the crash, which occurred in an area near Raupanga that Black Power regards as its territory.

MARTY SHARPE/ FAIRFAX NZ The Mongrel Mob members' car is kept afloat as police and air force crews work to fish it out of the water downstream from Hawke's Bay's Mohaka Viaduct.

It is understood the Gisborne CIB are investigating the possibility the crashed car, a white Honda, was run off the road.

"It would be foolish not to be aware of the gangs up here in the Raupanga area," he said.

Police had not yet spoken to any Black Power members on Monday, he said.

MARTY SHARPE/ FAIRFAX NZ The scene of a crash where three Mongrel Mob members died after their car plunged 150m down a sheer cliff at Mohaka Viaduct, northern Hawke's Bay, on Saturday.

They had spoken to the surviving crash victim after it happened, but had not had the chance to interview him formallysince he was discharged from hospital, Greville said.

Police found debris from a blue car at the scene, and were appealing to the public for sightings of it as they explored the possibility another car was involved in the crash.

Court records show Rigby was a father of at least two children, and had made efforts to leave the Mob and turn his life around.

He was jailed along with Stone for being part of an organised criminal group, after he turned up to a gunfight at the Wairoa Mob gang pad in 2010.

Rigby had turned up to help the gang's then-president, who had his patch stolen in a leadership quarrel, but then had driven away.

Rigby, who at that point had no violence convictions since 1992, surrendered his gang patch, and wrote a letter to a judge saying he wished to turn his life around.

The records showed Stone had a history of methamphetamine convictions, and had previously been jailed for threatening people, and other violence offending.

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* Mystery blue car sought in Mongrel Mob crash

According to Nathan Isaac's Facebook page, he was from the Hawke's Bay but had been living in Perth.

An air force helicopter was being used on Monday to hoist the crashed car out of the Mohaka River.

A policeman armed with a Glock pistol and a Taser stood guard at the scene on Monday morning.

A crowd of about a dozen patched Mob members, with women and children, were at the clifftop, weeping, as they awaited the helicopter's arrival.

The wreck rested about 300 metres upstream from the Mohaka Viaduct, being kept afloat by barrels.

The helicopter would take the wreckage to Gisborne for forensic examination, Greville said.

Wairoa Mayor Craig Little earlier downplayed the possibility of gang rivalry being implicated in the crash, saying such speculation was unhelpful to police.

He said there had been no unrest in Wairoa since the deaths and the town was in shock.

"On the gang stuff, there's no tensions in town.

"It's history, is what people have to realise. OK, these guys were Mongrel Mob members on their way to a hui or a celebration. They were also guys who had families, they were also someone's loved ones.

"The guy that survived will have a huge ordeal ahead of him now."

Little said the last crash he recalled at the viaduct was in the 1970s, before a barrier was put up at the clifftop.

Greville said earlier police could not confirm who had been driving the white Honda, who it belonged to, or how the other car might have been involved..

"We have found evidence at the scene that suggests a blue car may have been involved, but at this stage we have no more information about it.

"We'd like to hear from anyone who may have seen a car fitting that description travelling on the highway on Saturday afternoon."

WAIROA'S GANG CLASH PAST

After the 2010 gang pad gunfight, two Wairoa chapter members gave evidence against fellow mobsters from a rival faction at trial.

Later that year Black Power gang members shot a Mob rival in the arm and buttock on the forecourt of a Wairoa petrol station.

The hit was in retaliation for the shooting of a Black Power gang member in Wairoa a month earlier.

In 2011 a Mongrel Mob gang member was shot in the face and shoulder by a teenaged Black Power member.

Later that year two Porirua patch-wearing Mongrel Mob members set upon a 16-year-old at a Wairoa rugby match, then an associate fired gunshots into the crowd, where Black Power members were watching the match.

Hammer-wielding rival gangs brawled in front of children at Matariki celebrations in Wairoa in July last year.