Fifty-three passengers and crew were on board Flight NZ5067 from Christchurch which was diverted to Dunedin about 5.28pm.
Passengers spoken to last night reported a calm and controlled atmosphere during the incident, which was described to passengers as a "minor technical problem".
The spokeswoman said "as per standard operating procedure, the pilots called a local standby", alerting airport authorities to a potential problem with the flight.
The ATR landed without incident at 5.42pm and was with engineering for inspection, the spokeswoman said. Passengers were bussed to Invercargill about 7pm.
The emergency meant scheduled flights into Dunedin airport last night were delayed, affecting about 93 passengers.
Fire Service Southern Communications shift manager Karl Patterson said four pumps from Outram, Mosgiel, Lookout Point and Roslyn and a command unit from Dunedin were sent to the airport after it got the standby call at 5.28pm.
The call was that there was smoke in the cabin of a "heavy aircraft" and the plane was due to land at 5.30pm.
The fire service units were then stood down, leaving the airport fire service to takeover.
Janice Ramsay, an Invercargill freezing worker, said she had overcome a fear of flying to visit her son in Perth. Passengers were "very quiet" for about half-an-hour and the atmosphere was calm.
Southland Stags fan Corey Kingsbury, an architectural designer heading home from Christchurch to see his team defend the Ranfurly Shield against North Otago, was resigned to missing the game.
If the flight had gone as planned, he would have had about an hour to get to the game's kickoff at 7.35pm.
He was confident the team could prevail in his absence.
"They'll still win, hopefully."
Lloyd McCall, of Tapanui, was not impressed with a $6 meal voucher for each passenger, given sandwiches were $6.80 at the airport.
Passengers, some of whom had small children, were facing a long bus ride to Invercargill, he said. He was happy nevertheless to be "on the ground", and said Air New Zealand did the right thing.
The crew had a short debriefing with passengers after the flight, but did not "elaborate" on the problem, he said.
Adrian Sheat, who was travelling to Invercargill for a funeral, said a "slight fuelly smell" permeated the plane. The atmosphere was "mellow".
It seemed to "hit home" for passengers only when they saw fire appliances circling on the tarmac as the plane landed, he said.
