Wellington: A woman who gave birth in mid-air left the baby behind when she disembarked in Auckland, Television New Zealand reported on Thursday.

Police and Pacific Blue — the airline which operated the flight from the Samoan capital Apia — were saying little about their investigation on Thursday, but mother and child were said to be recovering in hospital.

Television New Zealand reported that the Samoan woman gave birth in one of the aircraft's toilets during the flight to Auckland on Thursday.

The infant was found by an airline worker in the toilet rubbish bin more than an hour after the plane landed.

There was no suggestion any of the 150 passengers or crew were aware that the woman, reportedly aged 30, had delivered mid-air.

But the television station said authorities discovered something was wrong after she approached them saying she had misplaced her passport. They noticed she was pale and blood-stained.

A police spokeswoman said an investigation was under way, but police had not been able to speak to the woman because she was undergoing a surgery in hospital. Police said they were investigating whether the airline had been advised the woman was in an advanced stage of pregnancy. Pacific Blue's website says women need medical clearance to board a flight if they have passed the 36-week mark in their pregnancy.

"We are relieved to have been informed that both mother and child are reunited, are well and are now being looked after in hospital," the airline said in a statement.

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