No charges will be laid following a federal police investigation into the "unbelievably negligent" disappearance of hundreds of classified documents from Prime Minister Malcolm Turnbull's department.

The country's most senior public servant, Martin Parkinson, is under pressure to explain how the documents disappeared from within his department inside a locked cabinet sold at a second-hand furniture sale in Canberra, ultimately winding up in the hands of ABC journalists.

ASIO staff deliver a safe to the ABC's Parliament House bureau on February 1. Credit:ABC screen grab

Mr Turnbull has said he wants heads to roll over the incident, which he described as "a disgraceful, almost unbelievable act of negligence" that beggared belief.

That will now be an internal matter for his department after the Australian Federal Police confirmed it had finished investigating the issue and would not lay charges.