The Transport Accident Investigation Commission says two crew members who died on a Korean logging ship had had no warning of the dangers of organic cargo, no rescue training and no emergency skills.
The commission on Wednesday released its findings on the death of the chief officer and the bosun of the TPC Wellington at Port Marsden in May last year.
The chief officer lost consciousness while he was climbing into the ship's hold and fell from the ladder onto the logs below. The crew member who tried to save him also passed out, fell and died within minutes.
The Commission says the men were killed by a lack of oxygen and the presence of toxic gases caused by the organic decomposition of logs.
It says oxygen levels in the hold were 1% - 3% - low enough to cause unconsciousness in seconds.
The Commission says the dangers from organic cargoes are well known in the maritime community, but the ship's crew had had no warnings on those hazards, no rescue training and no emergency drills.
It says it will forward its findings to the International Maritime Organisation.