The Council of Trade Unions says the number of prosecutions of forestry companies over deaths in the industry suggests not enough of these employers are being taken to court.
Forty-three forestry workers have been killed on the job over the past 10 years, but only seven prosecutions have been taken against the companies, the last one four years ago in 2013.
There have been five forestry deaths so far this year and Piripi Bartlett, 23, is the latest victim.
The father of two and partner died just three months ago, a day before the one-year anniversary of his cousin Niko Brooking-Hodgson's death at work in forestry. Both men left grieving families in the East Coast community of Te Araroa.
Mr Brooking-Hodgson's parents recently received the WorkSafe New Zealand report into his death, which ruled no legal action be taken against his employer.
CTU President Richard Wagstaff said the fact that only seven of the 43 deaths have resulted in prosecution of the employer company suggests not enough are being taken.
"Given that nobody should be killed at work and the vast majority of them go without any prosecution, that suggests to us that there aren't enough prosecutions," he said.
The CTU felt so strongly it took its own private prosecutions against two forestry companies last year. Both were successful.
Mr Wagstaff said WorkSafe should have taken those prosecutions instead of the CTU.
We couldn't find the evidence to show that the employer had done anything specifically wrong- WorkSafe deputy general manager Jo-Ann Pugh
"Given that the prosecutions were upheld, I think WorkSafe should have taken them. And I would like to think that they agree with that now too," he said.
Asked if if seven prosecutions from 43 deaths was acceptable, WorkSafe deputy general manager Jo-Ann Pugh said she can understand why people want to hold someone to account when a workplace death happens.
"But actually, the simple fact is you can do everything that you possibly can as an employer to manage your risks to your workers and still someone can die. And that doesn't always mean that a law has been broken. And in many of the cases that we've had over the year that's the situation," she added.
Asked if that means 36 of the 43 forestry deaths were just freak accidents, Ms Pugh said: "What we're saying is we couldn't find the evidence to show that the employer had done anything specifically wrong or not taken the correct action at that time. The cases that we did take we definitely had sufficient evidence to do."