Investigators have called off recovery efforts from the site of a plane crash in Antarctica, citing unsafe conditions.

The U.S. Antarctic Program and Antarctica New Zealand jointly decided to recall search-and-rescue teams from the site of the Twin Otter aircraft, after determining it would be unsafe to disturb the wreckage, where it remains embedded in snow and ice on a steep mountain slope, Peter West, spokesperson for the U.S. National Science Foundation, told in an email Sunday.

Recovery crews were able to recover the cockpit voice recorder, along with other equipment from the exposed tail of the plane. The recorder should provide information as to the cause of the crash, West said.

Crews were unable to recover the remains of the three crew members aboard the plane.

“With the advent of the Antarctic winter, and the generally poor weather conditions at the crash site, any renewed effort to recover the remains will need to wait until the next Antarctic research season,” West said.

He added the Antarctic research season begins in October, but given weather conditions and the remote location of the wreckage, it is not known how soon crews could return.

An earlier news release from Unified Incident Command, which was leading the recovery effort, said crews had intended to move the bodies to New Zealand and then Canada.

The aircraft, owned by Calgary-based Kenn Borek Air, was carrying three Canadians and went missing over the Queen Alexandria mountain range on Wednesday. The Canadians aboard are presumed dead.

The rescue team is expected to return to the National Science Foundation’s McMurdo Station and Antarctica New Zealand’s Scott Base later Sunday.

West said the Italian Antarctic Program and Kenn Borek Air have been advised of the decision to recall the team.

Transportation Safety Board spokesperson Julie Leroux told Sunday that the agency will decide in the next few days whether to send their own crew to conduct a technical investigation at the wreckage site.

“We’re gathering information, we’re doing interviews and we’re going to make a decision if we’re going to do a final report on this accident,” Leroux said.

Rescue teams located the wreckage of the Twin Otter aircraft on a steep slope along the route it had intended to fly, between the South Pole and an Italian base in Antarctica’s Terra Nova Bay, said Chris Henshaw, a search and rescue officer with the New Zealand Rescue Co-ordination Centre said Saturday.

Henshaw said Saturday it possible the plane may have turned too early while travelling through the mountain range en route to its destination.

The co-ordination centre said the impact appears to have been direct, making it unlikely that the three crew members aboard survived.

The pilot has been identified as Bob Heath from the Northwest Territories, an experienced pilot in both the Antarctic and Arctic. A second crew member was identified as Mike Denton from Calgary, and the third victim’s identity in the crash has been confirmed as Perry Andersen, of Collingwood, Ont.