Nearly 700 flights in and out of New Zealand carried a dead body in the cargo hold over the past year.
Customs has released figures under the Official Information Act showing 539 dead bodies arrived in the country and 191 flew out in the year till May.
With some flights carrying more than one corpse, this represented just 1.42 per cent of the 35,000 flights arriving in New Zealand.
In comparison, just 0.54 per cent of flights leaving New Zealand carried a corpse in the hold.
The majority of body repatriations came from Australia.
Gee and Hickton Funeral Directors general manager Gavin Murphy told Fairfax rules for sending bodies home across the Tasman varied from state to state and, compared with fares for the living, was much more expensive.
The total cost of repatriating a body could run to thousands of dollars once costs such as embalming, a hermetically-sealed casket, death certificate and other paper work was completed.
Transporting the corpse, plus casket, cost about $700 to $1000 to freight back to New Zealand in the unheated hold.
While repatriation from Australia took up to a week, coming from other countries, including England, could take up to three weeks, he said.
But getting a body cremated overseas then bringing the ashes back was a much cheaper option and with necessary customs clearance could even travel as carry-on baggage.
Funeral Directors Association chief executive Katrina Shanks told Fairfax she did not know specifically what happened to bodies of people who died on flights but said during medical incidents, passengers were taken to a quiet part of the plane, or the area around them was cleared.
She imagined the same would be true for bodies which, almost certainly being a sudden death, would be dealt with by police and the coroner on the ground.
According to a Customs statement provided to Fairfax bodies were not x-rayed or searched unless a risk to New Zealand's border had been identified.
"Importers and exporters of human remains are required to produce documentation to the airline verifying the casket has been hermetically sealed."