Carterton will hold a town meeting at the local fire station on Wednesday to discuss what caused local schoolchildren to fall sick on Friday evening.
A mysterious substance described as smelling "like poo" sent 15 people from South End School to hospital in moderate condition, while another 40 were treated at the scene with "very minor" symptoms.
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More than 100 people went through a decontamination process with the Fire and Emergency hazmat (hazardous materials) unit at the scene.
Everyone has now been discharged from hospital.
On Saturday police confirmed an investigation into the incident has been opened.
Officials have searched the ground and been unable to find any source for the mystery substance.
Police and the CAA were initally looking for the pilot of a grey and white plane seen flying near the school between 1:30pm and 2:30pm on Friday.
On Saturday Wairarapa Area Commander Inspector Scott Miller said a plane, which is now in the South Island, had been identifed as likely being the aircraft.
He doubted the plane was linked to the smell, but police would be speaking to the pilot.
Mayor John Booth told Newshub samples have been taken from near the school, but people are going to have to wait and see what actually happened.
"I believe there were samples taken last evening and we do have a full debrief this coming Wednesday evening in the Carterton fire station," he said.
"I'm hoping that at that debrief we may be given more information as to what may have caused this."
Mr Booth was full of praise for school administration's response to the situation as it developed.
"Once the grounds were cleared I went in with one of the local fire brigade guys and… saw [school principal Claire Crawford] in the staff room, he said.
"She was very relieved to have it over, I think we all were."
It's suspected a plane may have discharged something over the Wairarapa town, perhaps a fertiliser.
Anyone with further information is asked to contact Masterton police on (06) 370 0300.