A group of Australians have been stranded in a Tokyo airport overnight "without food or water", unable to leave due to Japan's strict COVID controls, after Jetstar cancelled their connecting flight from Finland to Australia.

Key points:

• Gordon Knight was flying with at least 20 other passengers from Helsinki to the Gold Coast, with a stopover at Narita
• When he arrived at the departure gate for his flight on Sunday night, there was no flight details and no staff to assist
• An email arrived soon after informing passengers the flight was cancelled

Gordon Knight was flying with his partner from Helsinki to the Gold Coast, with a stopover at Narita International Airport.

But when he and at least 20 other passengers arrived at the departure gate for his flight on Sunday night, there were no flight details and no staff to assist, he said.

An email arrived soon after informing passengers the flight was cancelled, forcing them to hunker down in a cordoned-off section of the mostly shutdown airport terminal.

"We were left to fend for ourselves," Mr Knight said.

"[Jetstar] didn't have bottles of water for us, didn't have any food for us, all of the shops were closed, and we were forced to sleep without a pillow or a blanket." 

Australians can ordinarily enter Japan without a visa, but the border has been shut during the pandemic and only opened in recent months to foreigners with a visa and a negative COVID test.

This meant the passengers were barred from leaving the airport.

But Jetstar were not aware of this, and passengers were told to find a "place" to stay for the night, Mr Knight said.

"They were entirely unaware of the COVID situation," he said.

"We pointed out to them that we couldn't do that. 

"It wasn't until about midnight that one of the staffers finally came back to us and said that they'd been unable to find any of these items.

"Jetstar had not prepared for something that they should have known was going to be inevitable."

Mr Knight said the situation was particularly concerning as his partner had recently had surgery.

"She wasn't really able to protect that leg," he said.

Airline cites engineering issues

Jetstar, which is owned by Qantas, said the plane was delayed for 24 hours due to an engineering issue identified prior to departure.

The flight is expected to leave Monday evening.