A 47-year-old man has been taken to hospital following an incident at a rural property in Central Otago involving cyanide.
Police said they were alerted to the incident in the Bannockburn area, near Cromwell about 6.15am.
"As a result of the information, police had concerns for a male resident's wellbeing in that area,'' Senior Sergeant Dave Scott said.
"The area was cordoned off and the male was located at about 8 o'clock this morning.
Ambulance officer and the Fire Service also attended.
"It involved decontamination of the scene due to the presence of cyanide," Mr Scott said.