A woman who lives near the scene said she heard a large, "nasty" crash before emergency services sped past her house to the scene.
Jody Blakemore lives near this morning's four-vehicle crash on State Highway 1 and told the Herald she could see what had happened in the early hours of the morning.
"It would have been about 6.25am and we heard this massive crash. We could just see over the rise at the end of the driveway. Someone had been trying to pull out and has been hit by the other cars coming towards them."
She says the stretch of road is notorious for near misses.
"To get into Ōtaki you have to pass two 100km/h passing lanes. You have to wait for the right time and most of the time that's almost impossible."
"Please avoid the area and consider using an alternate route," road authorities said.
Blakemore told the Herald she saw two helicopters fly towards the crash scene.
"When you see Life Flight you know it's serious.
"I just hope the families are OK. People need to pay attention not just to their safety but other people's safety on this road."
Motorists around the Ōtaki area were told to expect significant delays.
Waka Kotahi NZ Transport Agency in Wellington said about 6.30am the crash was blocking the road near Forest Lakes Rd.
"Please avoid the area and expect significant delays."
