It is unclear about why it was completing this ferry flight which started in Papua New Guinea the previous day.
Of interest, this particular helicopter featured on the CQ Plane Spotting Blog (as shown below) in 2015 when it was ferrying to Papua New Guinea from Archerfield wearing its 'old' New Zealand registration marking of ZK-HDY.
P2-HNZ is in fact this particular airframe's (c/n 36099) sixth registration marking - C-GAIN, N4110V, ZS-RVR, A6-AGS, ZK-HDY and now P2-HNZ.
UPDATE! Photos of P2-HNZ have appeared on the fantastic MRC Aviation (New Zealand) Blog which reports that on Thursday 20 September, P2-HNZ was offloaded at the Ports of Auckland then flown to Ardmore and onto New Plymouth.
Photo taken by Simon Coates ©