A Lear jet flying at 20,000ft, left for Christchurch about 3.30pm yesterday after completing 19 sweeps over Dunedin city and the Clutha district.
For several hours from mid-morning, the plane flew over the area in a recurring north-south pattern moving gradually west.
It flew as far north as Macraes Flat and as far south as Purakaunui.
The plane took off from Christchurch in the morning and returned just before 4pm.
A spokeswoman for private aviation jet company ExecuJet, which manages private jets using Christchurch Airport, confirmed the jet was doing aerial mapping work, but declined to say to whom it belonged or for which company the work was being done.
An Airways Corporation spokeswoman said she could only confirm it was a Lear jet and it flew at 20,000ft for the entire time it was above Otago.
A Civil Aviation Authority said use of airspace was the responsibility of the Airways Corporation.
Spokesmen from Land Information New Zealand and the Otago Regional Council, which both undertake surveys occasionally for map-making, said the jet was not doing work for them.
