The death toll from Cyclone Gabrielle in New Zealand has climbed to nine, as civil defence officials declare a major crisis in Gisborne.

Tairawhiti Civil Defence has asked tens of thousands of residents of Gisborne to stop using mains water as its treatment facility has failed.

"This is a major crisis," it said in a statement. "Our city has no water. Don't turn your taps on."

Four new deaths have been reported in the past 24 hours, almost doubling the overall toll, including George Luke, father of former South Sydney NRL star Isaac Luke.

During a visit to Hawke's Bay, Prime Minister Chris Hipkins addressed rumours the death toll was under-quoted.

"I have heard some outlandish claims out there ... it's no good to anybody speculating about how many people may have been injured or how many people may have died in this tragedy," he said.

"We will certainly share that information as soon as we can."

A New Zealand Herald report said Mr Luke was driving from Rotorua to Hastings on a back road during the peak of the storm on Monday night after bad weather closed the main highway when his car was hit by a landslip.

Located by helicopter on Thursday, Mr Luke and his partner were evacuated to Hawke's Bay Hospital, where he died.

While police are yet to confirm Mr Luke's death his hometown rugby team – the Hawera Hawks – made it public about 9am on Friday.

Flooded homes in the Esk Valley, near Napier, New Zealand. – AP

Two other deaths on Friday were reported by the media and confirmed by police.

On Friday morning, police said a person died in floodwaters near Waiohiki, southwest of Napier. 

News outlet Stuff said the deceased was a man in his 70s.

Stuff also reported the death of Rachel Greene, a 59-year-old woman, in Puketapu, west of Napier.

Ms Greene's body was found in the roof cavity of her home by her landlord's son on Friday.

Further tragedy struck in Muriwai, on Auckland's hard-hit west coast, with a second death of a volunteer firefighter.

Dave van Zwanenberg and Craig Stevens were trapped in a collapsing house on Monday night in heavy rainfall.

Mr van Zwanenberg's body was recovered on Wednesday and Mr Stevens died in hospital on Thursday night.

Fire and Emergency NZ (FENZ) chief executive Kerry Gregory said his crew was "still coming to terms" with the fact they'd lost two comrades.

"All of Fire and Emergency will feel his loss and my heart goes out to his family," he said.

A road between Napier and Wairoa has been washed out by floodwaters. – AP

A mother of a two-year-old who drowned in floodwaters in Eskdale, in Hawke's Bay, has also given a heartbreaking public statement of grief for her lost child.

Ella Collins said water filled her home up to 10cm below the ceiling and while her partner Jack helped her and four-year-old daughter Imogen survive, Ivy did not.

"Our wee Ivy was such a bright shining light," Ms Collins wrote.

"We were not wealthy at all but we lived such rich and love-filled days.

"This tragedy has cost us everything; our home and everything in it."

The rising death toll comes as first responders eye a spell of good weather which will improve prospects for rescue teams and recovery.

Major efforts are under way across the country to restore power and transport links, with flooding, landslips and tree falls blocking many roads.

Stories of heroism are emerging from the catastrophe.

FENZ Urban Search and Rescue team leader Ken Cooper said a man walked 70km from Putorino to Napier to help rescue workers.

"That's a day-and-a-half walk," he told Radio NZ.

"He walked to give us a list of people still trapped up in the East Coast."

A woman was killed in Putorino on Tuesday when a house collapsed on her under the weight of a landslip.