Travellers heading overseas are being forced to break their bubble because of the high demand for international flights after the lockdown.
One passenger on an Air New Zealand flight to Los Angeles was shocked to discover she had been seated next to a stranger.
The entire plane was full and there was not a spare seat on the aircraft, the passenger wrote on Twitter.
"I love how they are like "keep two metres distance when boarding" and then everyone is packed in," the passenger said.
"There's not one single empty seat on the plane. Completely unconscionable."
A spokeswoman for Air New Zealand told the Herald there were no recommendations about two-metre social distancing on international flights.
However, that was not the case for domestic flights where passengers would be separated by at least one metre under alert level 2.
"Air New Zealand is following Ministry of Health and WHO guidance to ensure flights are safe for crew and our customers," she said.
"All appropriate contract tracing measures are in place; we know where everyone is seated on the aircraft and we hold customers' contact details."
The airline was working to provide neighbour-free seating where possible on international flights, the spokeswoman said.
Because of the high demand for international travel as stranded nationals headed home after level 4, this was not always possible.
"Aircraft cabins also have hospital operating theatre-grade HEPA filters installed, which filter out viruses. Airflow is directed from the ceiling to the floor."
Enhanced cleaning was also taking place on aircraft, cabin services had been amended and changes made to the boarding and disembarking process.
Domestically, just under half of Air New Zealand's seats would be sold on turboprop flights and ticket sales on A320's would be just under 65 per cent.
Until the social distancing measures were removed, the airline would not be able to offer its lowest fairs to ensure operational costs were covered.
Air New Zealand would be running a limited schedule of about 20 per cent of its usual domestic services during level 2.
A spokesperson for the Ministry of Health said it had not provided any guidance on physical distancing requirements for international flights.
"The ministry is currently working with Air New Zealand on specific guidance for domestic travel," they said.