KEY POINTS:
Wreckage from the Air New Zealand aircraft which crashed off the coast of southern France last month is likely to lie on the seabed for several more weeks before an attempt is made to recover it.
The Airbus A320 plunged into the sea near Perpignan on November 28, killing all seven people on board - five New Zealanders and the two German pilots.
The A320 was in its final assessment before it was handed back to Air New Zealand after it had been leased by the German airline XL Airways.
New Zealand authorities sent the Transport Air Investigation Commission's (TAIC) deputy chief investigator Ken Matthews to France as part of the official inquiry.
He was now heading home.
TAIC chief investigator Tim Burfoot said there was little more he could do and the inquiry could take months or years.
He told NZPA today the wreckage was in a difficult place on the seabed with a strong current and was spread over two kilometres.
"The wreckage recovery is really difficult. Conditions have been pretty bad and things have been pretty fragmented.
"They (French investigators) are still mapping the seabed and finding out where it all is and they possibly won't get to start recovering that until the New Year."
TAIC in New Zealand still had no idea what had happened.
"Anything would just be speculation at this stage. The information is still being gathered.
"They are looking at radar traces. It is the one thing they have got but that is pretty raw data."
He could not confirm the latest report that a fourth body had been found.
It was hoped the three bodies already recovered could be identified this week through DNA records.
He said the inquiry could be long and difficult.
"These ones can go on for years. If you have to rely on piecing the wreckage together, recovering as much of it as you can and piecing it together to try and find out, you really are talking a long, long time down the track."
The inquiry was one of the most difficult New Zealand investigators had been involved in because the wreckage had to be recovered from the sea, he said.
Other difficult air crashes at sea in New Zealand included a Convair mail plane crash off the Kapiti Coast in 2003 which killed two pilots, and a Cessna 402 which crashed into Foveaux Strait in 1998, killing a pilot and four passengers. Five survived.
The Airbus crashed 29 years to the day since New Zealand's worst air disaster, when an Air New Zealand DC10 hit the side of Mt Erebus in the Antarctic, killing all 257 passengers and crew.
- NZPA
