Eight soldiers have been taken into police custody and then to the hospital after taking an unknown drug in Palmerston North last night.
Police were called to the central city just before 4am today and found the men seriously ill.
Police said the men were initially taken into custody but as they were suffering the effects of an unknown drug, the men had to be taken to the hospital for treatment.
Police said they were trying to find out what the drug was, and where it came from.
They would not confirm if charges would be laid.
Palmerston North police said they would not comment any further as it is now a matter for the Defence Force to deal with.
In a statement, the Defence Force confirmed several soldiers were taken into custody.
Defence said it was up to the police to lay any criminal charges, but would not comment on whether the breach of any military rules was being investigated.
