Judith Hamel, a doctor, said airline staff alerted her when the woman went into labour. 'There were four of us: one surgeon, one orthopaedic surgeon, one kidney specialist and a humble general practitioner who was the only one who'd done very much in the way of deliveries, so I got that end,' she told Australian Broadcasting Corporation News.

'I got the operative end, one got the comforting end, the 'breathe, breathe, breathe' end, and the other got the looking-after-the-baby end.

'I think we all had fun once we knew it was all safe,' she said, adding that it was a smooth, 'fun' birth.

The labour forced the plane to land in Darwin, where mother and son were rushed to Royal Darwin Hospital. The other passengers then continued their journey.

The hospital said the baby was about six weeks early, but was healthy and weighed 2.7kg.

The boy was breathing unaided in the hospital's special care nursery, and the mother was recovering in the maternity ward.

The father, Jagdar Jagdar, said he had spoken to his wife.

'I was wishing to see my wife at the time but all that happened,' he said.

There were tears in his eyes when he was told about the birth of his son, and he had been 'very, very worried' about his wife.

Mr Jagdar said he was relieved that his family was doing well and anxious to get to Darwin.

Cathay Pacific said it was delighted at the birth. It said women who were 28 weeks or more pregnant had to provide a doctor's certificate stating they were able to fly.

'Women who are 36 weeks pregnant are banned from flying with us,' a spokesman said. 'For women carrying twins, 32 weeks is the limit.'

The airline said children born on a plane would not enjoy a lifetime of free air travel, as was sometimes believed. 'Sorry, there is no such policy,' the spokesman said.