A fire union has warned its members to have someone else present when meeting with a manager who is facing allegations of "bullying".

It follows several complaints of bullying or harrassment between firefighters in recent years, some of which have ended up before the Employment Relations Authority.

In one workplace bullying case in 2014 the then Fire Service was ordered to pay a female fire investigator $5250 plus costs after the ERA was critical of its disciplinary investigation process.

This week the New Zealand Professional Firefighters Union Auckland Local Committee issued an alert on its website, urging members not to attend any meetings alone with the Fire and Emergency New Zealand [FENZ] manager.

"The Local is aware that [the manager] has had at least three complaints of bullying behaviour against him," the memo said. "Two of these involve members."

"As a result, the Local makes the strongest recommendation to members that no one speak with or engage with [the manager] without at least one other member present.

"If you are requested by [the manager] for a meeting of any nature, do not attend until a representative of the Union Local can also be present."

Auckland Local Committee secretary John Waldow said the union believed it necessary to issue the warning about the manager, who the Herald on Sunday is not naming.

"We feel that we need to protect our members if they have any dealings with this person," Waldow said.

"Currently there are two complaints against him from staff in his area."

One of the complaints, made by a fire investigator, is understood to have prompted an investigation by FENZ and a decision on the report is expected next week.

Waldow said the union was concerned there had been no resolution after almost 12 months.

"We have concerns that our members have been treated unreasonably, that there have been months and months of delay in the investigation."

He could not detail the alleged behaviour but called the complaints "legitimate and genuine".

"We feel that had this been handled correctly from the beginning this manager should have been suspended and stood down until the incidents have been properly investigated and resolved to the satisfaction of those concerned."

The Herald on Sunday understands the third complaint was made by a volunteer fire chief.

The manager said through a FENZ spokesman that he did not want to comment.

FENZ said it could not respond to questions about the complaints because it could not comment on "employment matters".

However a spokesman said FENZ's policy relating to bullying was last reviewed this year and substantially updated in 2015.

Among other things, the policy requires personnel to:

• Treat everyone fairly and respect the rights of other Fire and Emergency New Zealand personnel and the public;

• Refrain from discriminating against or harassing other personnel, and;

• Respect the cultural background of other personnel and all members of the public.

Waldow said the memo was taken down from the NZPFU website on Friday at the instruction of the union's national president, Peter Nicole.

Nicole did not return calls.