The DL Marigold arrived in Tauranga from Indonesia on March 4. It had been due to stay in New Zealand waters for 9 days.
The ministry understood the vessel would go to Fiji for cleaning. It would then return to New Zealand to finish discharging a shipment of palm kernel expeller.
"The vessel won't be allowed back until it can provide proof it has been thoroughly cleaned," Mr Gilbert said. "We were dealing with severe contamination in this case."
Mr Gilbert said it was the first time the ministry had ordered an international vessel to leave a New Zealand port for biofouling reasons. As of 11.30am Tuesday, it was off shore from Whangarei.
New rules will require all international vessels to arrive in New Zealand with a clean hull from May 2018.
Until then, the ministry can take action in cases of severe biofouling.
Biofouling is when marine pests and diseases are brought in on vessel hulls. It is considered a threat to New Zealand's marine resources.
Deliberate non-compliance with the new biofouling standards, or negligence leading to non-compliance, can spark inspections or audits in New Zealand.
DL Marigold
Owner: Daelim, South Korea
Flag: Panama
Ship type: Bulk carrier
Gross tonnage: 23,500
Length: 180m