A sailor is staring down the barrel of 19 charges relating to the use, procurement and supply of a banned substance.

But the nature of the charges, including the type of substance, remains unknown.

The NZ Defence Force (NZDF) said in a statement on Tuesday the sailor would face a court martial on September 28 at the Devonport Naval Base in Auckland.

The statement gave no further information besides the number of charges and that they related to allegedly using, procuring and supplying an unnammed banned substance.

In February, two sailors court martialled for offences including dealing ecstasy were sacked and sent to military detention.

A court martial is the military equivalent of a civilian court.

It tries cases where a breach of military discipline or other offences may have occurred.

Possible sentences are prison and dismissal from the forces, detention at Burnham military prison or within other camps, demotion, a severe reprimand or a fine.

A judge is appointed to preside over the court martial and will decide whether the accused is found guilty or not guilty.

A panel of senior military members is present for the trial and, if the accused is found guilty, will decide the sentence.

Appeals may be made, in certain circumstances, to the Court Martial Appeal Court, then to the Court of Appeal or the Supreme Court.