The road death toll for the holiday weekend, which officially ended at 7am Tuesday, stands at six - the worst for several years.
The latest fatality occurred following a crash on State Highway 2 at Waihi yesterday evening.
Seven people from that incident were taken to Tauranga Hospital with critical to minor injuries.
The holiday period began at 4 o'clock on Friday afternoon.
Police said one person was killed after a vehicle containing eight people rolled on State Highway 2 at Waihi in the Hauraki District about 5pm on Monday.
St John Ambulance said one person was flown to hospital in Tauranga in a critical condition, while six occupants were taken to hospital via ambulance with serious to minor injuries.
Earlier on Monday, a woman died after being struck by a bus in Porirua.
On Sunday, Matthew Edward Carpinter, 31, of Kaiapoi, died after his motorcycle lost control and hit a bridge on State Highway 6 near Greymouth. Police are investigating the crash.
Two women, aged 79 and 53, died in a head-on crash near Taupo on Saturday, and a 16-year-old boy was killed when a four-wheel-drive vehicle left a track and rolled into a river east of Nelson.
National manager of road policing Superintendent Paula Rose said she is deeply saddened at the death toll - the highest since 2001.
Ms Rose said though alcohol did not seem to be a factor, speeding seemed to be a trend in some crashes and the death toll is a tragic reminder for people to slow down.
Police warned drivers to take extra care as they headed home on Monday, with conditions likely to deteriorate as rain is forecast for most of the country.
Motorists are urged people to think ahead, drive to the conditions and keep plenty of space between themselves and the car in front.
The lowest road toll for Labour weekend was recorded in 2006, when three people died.