Days after 1 NEWS revealed Air New Zealand's been secretly helping the Saudi military, questions remain unanswered over its work for another nation, also involved in the war in Yemen.
There's also growing concern that the airline is being allowed to investigate itself.
The war is still raging in Yemen, a Saudi-led coalition fighting Iranian-backed forces, fuelling the world's worst humanitarian crisis.
Air New Zealand has now launched an internal investigation into why it was helping the Saudi military, but some say that's not good enough.
"Given the gravity of the situation and the seriousness of potential human rights risks, we think it was important that a review is independent to ensure that they're properly understanding what happened," Amnesty International's Lisa Woods told 1 NEWS today.
Alexander Gillespie, an international law expert, agrees.
"No one should be able to investigate themselves and then report on it," he says.
But that's exactly what is happening. Finance Minister Grant Robertson says Air New Zealand has an "obligation here to New Zealanders to get to the bottom of what happened".
This evening Air New Zealand told 1 NEWS it is in the process of "appointing external advisers to assist with our internal review."
The team that was servicing the Saudi navy engines also works for other military and commercial clients.
It's been open about its contracts with the Australian and United States navies, but it appears to have also had customers in Iraq, Oman and the United Arab Emirates as well as Saudi Arabia.
"I'm aware we've had some business with the UAE, I'm not aware that we have business at this stage through the gas turbines business with Iraq," Air New Zealand chief executive Greg Foran says.
The United Arab Emirates is also involved in the war in Yemen, so what has Air New Zealand been doing there?
"As I understand it, it was also working on engines," Foran says.
"I'm not across the details at this stage as to whether that was to do with navy vessels."
Woods says it's "deeply concerning".
"For me, what that shows is clearly there are deep problems with Air New Zealand's processes in that area, and that to me hammers home an independent process."
Others are bewildered the airline hasn't clarified the situation around its other customers.
"This is the kind of reason we need to have a wide independent investigation," Gillepsie says.
The extent of Air New Zealand's work for other foreign militaries is still murky.
The Ministry of Foreign Affairs and Trade is also looking into the legality of the work undertaken by the airline.