An investigation to find the ship that spilled a toxic fumigant near the Poor Knights Islands in April has uncovered a gap in international fumigation standards, but has been unable to identify the offending ship. The Magnesium Phosphide cargo fumigant, which was packaged in about 50 cardboard tubes, was active and a danger to the public so a major recovery operation was carried out. During its investigation into the incident, Maritime New Zealand identified a gap in international legislation surrounding a lack of standards that prohibit Magnesium Phosphide being discharged at sea. Maritime NZ has bought this to the attention of the International Maritime Organization, so other incidents such as this can be prevented.