They are among 440 fishers from Russia and
the Ukraine, 270 of whom are due to go out on three Independent Fisheries boats next month.
It follows the discovery on Monday that eleven of the fishermen had returned positive results for Covid-19.
Seven more of the group tested positive yesterday.
The total number of active cases of Covid-19 in New Zealand is 66.
Air Commodore Darryn Webb told Chris Lynch on Newstalk ZB on Tuesday they are expecting the number of positive cases within the fishermen group to increase.
"I think it's logical to expect that. We knew in the planning that places like Russia are high risk."
Webb said it was not an "uncontained outbreak" and something that happens in our facilities.
The processes were robust and fit for purpose.
"We have an exclusive use facility for these fishermen. Part of the process early on is that we do know they are coming from a high risk area so let's provide them a single location."
He said there was a 24-hour delay as the aircraft worked through its process in Moscow and the fishermen were assembled there for 48 hours and then en route for 18 hours.
That period of time provided an opportunity for the virus to spread.
"That could well be an exposure risk factor."
