SYDNEY - Parts of Queenstown airport in New Zealand was evacuated on Sunday (July 24) after a bomb threat was found on a Qantas plane, media reports said.

The alarm was raised after a cleaner reportedly found a note on board the B737 that had arrived from Sydney at about 3pm, the Guardian reported.

There were no passengers onboard at the time the note was discovered, it said.

The police bomb squad searched the plane but found no evidence of a bomb, reported Sydney Morning Herald.

Baggage and the terminal building were still being searched and authorities were making inquiries with passengers.

A police spokeswoman said a cleaner found the note on the plane after it landed and alerted police.

Air New Zealand cancelled two domestic flights into Queenstown after the scare, Sydney Morning Herald said.

The Qantas plane was scheduled to return to Sydney at 1:25pm AEST but was delayed until after 3pm.

"Everyone seems to be pretty relaxed, to be honest. There's been no announcement made to us," local resident Fraser Mackenzie, who said he was at the airport to pick up an unaccompanied minor, told the paper.

Other planes were still taking off from the airport, he said, adding that he had seen three or four fire engines at the scene.

The terminal reopened later on Sunday afternoon with the airport warning passengers of delays, Sydney Morning Herald said.