The Netherlands is sending 40 unarmed police to the crash site of flight MH17 in rebel-held Ukraine and is seeking a means to "further stabilise the area".

Dutch Prime Minister Mark Rutte said stabilising the surroundings "requires international discussions, it requires a legal mandate".

Malaysia Airlines flight MH17 was shot down with 298 people on board a week ago over rebel-held territory in eastern Ukraine in as-yet unexplained circumstances.

Dutch authorities say they can only be sure that 200 corpses have been recovered and no recovery efforts appear to be under way for more bodies or remains. 

There is also concern that the crash site has not been secured.

"It's absolutely not certain that this is all going to work. It's very complex and requires many partners," Mr Rutte told journalists.

"This must happen very carefully, which is why the cabinet is seeking ways to strengthen our commitment on the ground in the coming days, but that will happen step-by-step and very carefully," he added.

A bolstered team of 23 investigators will be sent to the area, "accompanied by 40 unarmed royal military policemen," Mr Rutte said.

The police will also be tasked with helping to recover bodies, he added, describing the security situation in the area as "changing".

He refused to comment on reports that the Netherlands and Australia are drafting a new UN Security Council resolution to allow armed police or troops to secure the crash site.

"The cabinet is working on several options that should help to create a more stable environment for bringing back the remaining victims," Mr Rutte said.

Australian Prime Minister Tony Abbott, whose country lost 28 citizens in the disaster, said that there was still a need for a rigorous search of the site.

Fifty Australian officers are on stand-by in London.

At the crash site, the Organisation for Security and Co-operation in Europe (OSCE) monitoring mission said that an Australian policeman had been inspecting the security situation in the area.

"The Australians are getting a sense of the security for the area, they're mapping it, they're getting a sense of where the crash sites are," OSCE spokesman Michael Bociurkiw said.

Meanwhile, Russia's Interstate Aviation Committee has said the black box flight recorders from the Malaysian airliner downed over Ukraine suffered slight damage but this would not affect the data.

The statement said there was no evidence the flight recorders had been tampered with.

Russia is among the countries participating in the analysis of the recorders.