WorkSafe New Zealand has filed charges over the 2019 White Island volcano tragedy.

In December last year, the Whakaari volcano erupted, killing 22 people including 17 Australians.

WorkSafe NZ says it has filed charges against 13 parties over the incident, but they cannot be named yet as they have the right to seek a suppression order on their names.

There are 10 parties facing charges carrying a maximum fine under New Zealand's Health and Safety at Work Act of $NZ1.5 million ($1.4 million).

Three individuals face charges too.

“There are three individuals charged under section 44 of the act which requires directors, or individuals with significant influence of a company to exercise due diligence that the company is meeting its health and safety obligations under the act,” WorkSafe NZ said in a statement.

“Each charge carries a maximum fine of $NZ300,000.”

Worksafe chief executive Phil Parkes said the investigation was the “largest and most complex” ever undertaken by the organisation.

He also acknowledges that the victims and their families and friends will find it frustrating that he cannot name the parties involved.

“My hope is those connected with this terrible tragedy will get comfort from knowing those we consider did not meet their obligations will have to account for their actions and inactions in court,” Mr Parkes said.

“In the last decade there have been significant approaches to health and safety in New Zealand but there is much much more to do. Today I'm asking every workplace to make changes to how your work is done.”

The Worksafe statement suggested there may be other legal action relating to other parts of the tragedy.

“WorkSafe did not investigate the rescue and recovery of victims following the eruption,” the statement said.

“On those matters, no enforcement action has been taken. Those actions may be the subject of other proceedings, such as coronial inquest.”