Wellington, Aug 9 (IANS): Eleven of the 21 crew onboard container ship Rio De La Plata, currently at sea off the coast of New Zealand's Tauranga, tested positive for Covid-19 on Monday.

The Ministry of Health said in a statement that it is likely that at least some of the 11 crew are active cases of Covid-19 and further test results will help determine how many of the crew are likely to be historical cases and no longer infectious, the Xinhua news agency reported.

Public Health staff took the test swabs in Tauranga from the crew as part of the requirements for entry for the vessel to Napier, the ship's next stop.

All of the crew on board are reported to be well, with none reporting any symptoms.

The ship is linked to a Covid-19 case in an Australian pilot who was onboard the vessel in July in Queensland and who later developed symptoms and then tested positive for Covid-19 nine days after being aboard the vessel. The Australian pilot is confirmed to have the Delta variant and has not been linked to any other Queensland cases.

Initial concerns about the link with the Australian pilot resulted in loading of the vessel being temporarily halted on August 4 in Tauranga. An assessment was carried out before unloading was allowed to resume the following day.

As an additional precautionary measure, 94 port workers who as part of their work, spent time on the vessel while it was in port, are now being contacted, provided with advice, tested and stood down until a negative result return.