The death toll from Cyclone Gabrielle in New Zealand has climbed to nine, including the father of a former NRL star.

Four new deaths have been reported in the past 24 hours, almost doubling the overall toll.

Social media is awash with speculation of an under count in deaths, with Prime Minister Chris Hipkins acknowledging community concerns.

"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."

Police and emergency services simply do not know what a final death toll may be, with many remote settlements still inaccessible and without communication lines.

There have been more than 4,500 people reported to police as uncontactable, and 80 people have been tasked with working through the lists, escalating cases of key concern.

"We're not talking huge numbers," Mr Hipkins said of an expected death toll.

"It's not like I'm aware that there are lots and lots and lots out there that we're doing not reporting.

"We will share that information as soon as we're able to."

Mr Hipkins visited Hawke's Bay on Friday, the site of major destruction under the weight of burst rivers and huge flooding.

Six people have now died in the region, including George Luke, father of former South Sydney NRL player Isaac Luke.

The NZ Herald reports Mr Luke was driving from Rotorua to Hastings on a back road during the peak of the storm on Monday night 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.

Two other deaths were confirmed on Friday.

Police say a person died in floodwaters near Waiohiki, south-west of Napier, which news outlet Stuff says is 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.

'A bright shining star'

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 in the scramble to find shelter, her daughter Ivy was lost in floodwaters.

"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.

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