The Herald on Sunday revealed one of the new helicopters had been grounded after a lightning strike damaged all its rotor blades and unspecified structural parts of the craft. Aviation experts said the damage could run as high as $10m.
Further questions about the fleet, including compensation for the delayed delivery, were subsequently treated as requests under the Official Information Act.
Now the ministry has confirmed French-based NHIndustries is providing compensation, including paying the $1.8m bill to charter an Anatov plane for the first delivery.
Other compensation included scheduled improvements; services free of charge and some at a discounted rate; additional training; personnel to assist with introduction into service; extended warranties; and guaranteed flying hours.
Specific financial details of the compensation package were deemed too commercially sensitive to release to the public.
Quilter said a certification schedule by Nato nations was behind the delay, plus a decision to get the latest software developments into the New Zealand-bound craft.
This followed a hold-up to install the electronic maintenance data for the aircraft. As with all major defence contracts, there was provision to impose penalties for delays in delivery, she said.
Labour defence spokesman Phil Goff was critical about the lack of disclosure about the damaged NH90.
"Why are they being so secretive about it? It was an act of God."
He said it took a series of parliamentary questions to be told the lightning strike had damaged the lamination of the crippled NH90's tail and main rotors.
Goff said given the delay, compensation from the manufacturer was appropriate though it appeared NHIndustries was getting off lightly.
"That delivery payment is a gesture, not a significant dent," he said.