More than 30 Defence Force personnel have been charged with using or selling drugs in just over a year.
Figures provided to RNZ News under the Official Information Act showed that since December 2014, there had been 31 summary trials for charges relating to drug use or sale.
Of those tried, 28 were found guilty, and three quarters of them had since left the force.
Before December 2014, data on controlled drug offences was not held centrally by the force and so was not provided.
Late last year the Chief of Defence Force announced a zero-tolerance policy on the use of illicit drugs.