Police are remaining tight-lipped as to exactly what's happened but the Herald has learned a rescue helicopter is on its way to the scene near Matamata.
A community is reeling after a woman was found dead and a baby suffered critical injuries during an incident in Matamata just a day out from Christmas.
"So tragic, there is no winners in any of this – very, very said," said Matamata Piako District Council Mayor Jan Barnes, who said she had been rocked by the tragedy.
Waikato police Detective Senior Sergeant Stephen Ambler said emergency services were called to a Matamata property at 1pm today.
A man at the property, who was known to the woman, has been taken into custody.
A baby at the property is fighting for their life after suffering critical injuries. The baby was airlifted to Waikato Hospital and is now being treated in the Intensive Care Unit.
It is understood the property was rented.
Jamie Kennedy, a farm manager of a neighbouring property, said he just had arrived back to find emergency services had cordoned off the property.
There were three different houses down the next door driveway, he said.
"I just came back from golf and thought, 'What the hell's going on down there'."
He had no details about the tragedy that had occurred.
Blandford Lodge stud director Graham Bax told Stuff the Westpac Rescue Helicopter had arrived at the scene, which was directly behind his property.
"There is a bit of activity going on ... I'm about 200 metres away," Bax told Stuff. "I went out to see if the horses were OK, because I was a bit worried about the noise of the helicopter frightening them."
An ambulance and police vehicles are also attending.
A woman posted on Facebook: "Heard the sirens before. Very sad, sending my love to the women [sic] who has passed and that poor little baby xxx."
Another neighbour believed a brother and sister lived at the property.
"We have seen her pushing a pushchair with the baby in it down the driveway," they told Stuff.
"They haven't been living there very long a couple of months."
The Herald understands the chopper responded to a house on State Highway 27, Matamata.
The 19-year-old disappeared without her wallet or mobile phone.