The airport activated its emergency security protocols after a note mentioning a bomb was found by a cleaner on a Qantas flight from Sydney after it landed at 2.14pm.
Senior Sergeant Paula Enoka, of Queenstown, said the investigation was continuing and witnesses spoken to so far had been cooperative.
She would not comment on the note's wording or other features, and said police would only make the note public if it was useful to the investigation to do so.
Were police to catch the person responsible, it was too soon to say what penalties they might face, Sen Sgt Enoka said.
Police and airport staff began evacuating the terminal about 3.20pm. Police, Aviation Security and dog teams searched the Boeing 737-800 plane, the terminal and baggage for about an hour, but nothing was found.
The scare caused disruption for hundreds of passengers and led to the diversion of two incoming domestic flights and the cancellation of three outbound flights, including an international flight to Sydney.
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Police and airport staff evacuated the terminal after a note mentioning a bomb was found by a cleaner on Qantas flight QF-121 from Sydney.
Officers, Aviation Security and dog teams searched the Boeing 737-800 plane, the terminal and baggage but nothing was found.
The bomb scare, coming so soon after terrorist atrocities in Europe and the US, made some passengers nervous about flying, including 12-year-old Auckland girl Alexandra Lyne.
But her father, Neville, was not so concerned.
"It doesn't really make me nervous,'' he said.
"I don't think anything like that would happen down here; it's one of the advantages of being so isolated.''
"It's more inconvenient than anything else,'' Mr Lyne said.
The note was taken to Queenstown Police Station and investigations are continuing. No arrests had been made by yesterday evening, a police spokeswoman said.
The jet remained on the tarmac close to the arrivals door while the terminal was evacuated, about 3.30pm.
The search took about an hour.
Flights continued to take off and land during the early stages of the evacuation, although passengers disembarked away from the main terminal.
Arriving international passengers who had not passed through customs were separated from the crowds and shepherded into the Hertz car rental yard.
Ben Osborne said he was trying to get back to Auckland and it looked like he would miss his flight.
"What can you do, though?''
Queenstown Airport Corporation spokeswoman Jen Andrews said during the incident two Air New Zealand flights from Wellington and Auckland were diverted to Christchurch and back to Auckland respectively.
The two corresponding outbound flights to Wellington and Auckland were cancelled.
An Air NZ flight to Sydney was also cancelled because it was not night-flight capable and missed the Civil Aviation Authority twilight cut-off.
All other evening services were running to schedule. A Qantas representative declined to comment.
- additional reporting Guy Williams
