The smell from leaking sinks caused a Virgin Australia flight to Sydney to be diverted back to Los Angeles.
But the airline denied reports by some passengers that there was human waste running down the aircraft aisles.
Passengers told New Zealand radio the stench was ‘unbearable’ and said they saw human waste going through the aisles.
But the airline told the Sydney Morning Herald the onboard toilets operate on a completely separate drainage system to the sinks, which were the cause of the problem, and said there was no leakage of human waste.
Virgin Australia said the flight was turned around for the comfort of passengers, whose safety was never called into question.
Flight VA2 landed at Los Angeles at 4.09am local time this morning (Tuesday).
Passengers were put up in hotels overnight and were due to depart for Sydney at 19.55 local time.
Virgin Australia said the aircraft has now been inspected by engineers and cleared to return to service.
An investigation into what caused the problems is now underway.
