Five soldiers from Linton Military Camp have been kicked out of the army after taking N-Bomb, a psychedelic drug.

The soldiers were part of a group of eight who were taken into custody over Labour Weekend in Palmerston North after they were found acting strangely in the city centre and it was suspected they were on drugs.

Of the three remaining soldiers involved in the Labour Weekend incident, two have elected to be tried by court martial and one has been referred for court martial.

READ MORE: Soldiers hospitalised in Palmerston North after taking mystery substance

Linton Military Camp commander 1 (NZ) Brigade Colonel Hugh McAslan said the behaviour was "disappointing".

He said drug use "erodes trust", and trust was crucial in their line of work.

"It's absolutely fundamental to what we do.

"We've got to be able to trust our team-mates and know they are drug-free for our own wellbeing and confidence when... working alongside them."

McAslan said drug use was an issue they were tackling head on.

"We're being very vigilant around this.

"It's an issue we're going to deal with, and we will deal with it."

He said they expected their employees to hold themselves to a high standard, which he thought was what the country expected of them as well.

"New Zealand probably expects its army to be [a] professional and capable force and when it deploys overseas [expects it] will perform to [the] best of its ability."

Any case of behaviour that was incompatible with their values and ethos was "disappointing".

The New Zealand Defence Force's chief of army Major General Peter Kelly said he would do "everything he can" to ensure the New Zealand Army was free of illegal drugs.

"I am well aware of the current illegal drug issue throughout New Zealand and I will not stand by and let illegal drugs pollute the integrity of the New Zealand Army.

"I am exceptionally proud of our army and I am determined that the actions of a few must not undermine the professionalism and pride of the majority," he said.

STANDARDS

Kelly said he was saddened that a few people marred the efforts of the majority.

"We are a military force charged with maintaining the security and freedom of New Zealanders and those countries we work alongside and we must be at the top of our game.

"I have sent a message to every soldier in the New Zealand Army outlining my high expectations and the consequences should they choose to not heed that message.

"If any soldier is caught taking illegal drugs or having illegal drugs in their possession, they will be dealt with to the full extent of the NZDF's ability."

Barrister Michael Bott, who is representing one of the soldiers yet to go through the court martial process, was unimpressed by some of the comments made by Kelly and McAslan in response to the issue.

"The reported remarks of Linton Military Camp Commander Brigade Colonel Hugh McAslan and NZDF's Chief of Army Major General Peter Kelly, referring to an effective zero-tolerance policy and if any soldier is caught taking drugs, being "dealt with to the full extent of the NZDF's ability" are improper when three of the eight soldiers have yet to have their cases heard via court martial," Bott said.

"As counsel representing one of the two who have elected this route I am disappointed that these remarks are being made, when the 'trial' process is just beginning.

"People may take drugs without realising it, for example. The young man I represent joined the army ready to put his life on the line for his country. It is therefore disturbing to see figures of authority so ready to discard the future of a young man for the sake of a quick PR point."

NZDF staff underwent random drug testing as well as testing at various levels of their career, with strict guidelines followed to ensure the process was accurate and fair.

Kelly said the New Zealand Army was a disciplined and professional organisation that held the values of courage, comradeship, commitment and integrity at its core.

Earlier this week a Linton Military Camp soldier was sentenced to 28 days in the Services Corrective Establishment in Burnham after being found guilty of four drug-related charges and one alcohol-related charge unrelated to the Labour Weekend incident.