Difficulties gaining access to the MH17 site, its overall size and trauma to victims’ bodies have led to doubts over whether all remains can be recovered.

Australian Federal Police officers are preparing for the possibility that not all human remains from the downed MH17 aircraft will be recovered.

A Dutch-led police mission will make a second attempt to gain access to the crash site in eastern Ukraine on Monday after it was forced to abandon a bid on Sunday because of intense fighting in the area.

The 49-person mission that includes 11 AFP officers is waiting for the go-ahead in the rebel-held city of Donetsk, about 60 kilometres away.

AFP deputy commissioner Andrew Colvin says there is a possibility they won’t get to the crash site in the near future.

“Of course it is a highly volatile area,” he told reporters in Canberra, adding that safety was paramount.

Mr Colvin warned of the difficult circumstances the mission faces, including the size of the crash scene, trauma to the bodies of victims, and complications gaining access to the site almost two weeks after the Malaysia Airlines plane was brought down by a surface-to-air missile.

“We have to prepare ourselves for the possibility that not all remains will ultimately be recovered,” he said.

Russian-backed separatists have agreed to allow an unarmed international police team to recover more bodies and start a forensic examination of wreckage.

In all, some 170 unarmed AFP officers have been deployed in Ukraine as part of the recovery effort.

A total of 298 people, including 37 Australian residents and citizens, were killed in the disaster.