Britain has joined a chorus of countries calling for a UN-backed tribunal to prosecute those responsible for downing flight MH17, as relatives remembered their dead in ceremonies on the first anniversary of the disaster.

All 298 passengers and crew - the majority Dutch - died on July 17 last year when the Malaysia Airlines Boeing 777, on a flight between Amsterdam and Kuala Lumpur, was shot down over rebel-held east Ukraine during heavy fighting between Ukrainian forces and pro-Russian separatists.

Kiev and the West point the finger at the separatists, saying they may have used a BUK surface-to-air missile supplied by Russia to down the plane. But Moscow denies involvement and instead accuses Ukraine's military.

"Justice must be delivered for the 298 innocent people who lost their lives," British Foreign Secretary Philip Hammond said in a statement on Friday.

"That requires an international tribunal, backed by a resolution binding all UN member states, to prosecute those responsible."

On Friday, News Corp Australia released new footage which it said showed Russian-backed rebels rummaging through the luggage of dead passengers among the plane's smouldering wreckage.

It said the video, smuggled out of the fighters' Donetsk base and only obtained this week, was filmed by the rebels themselves as they investigated what they initially believed to be a Ukrainian air force fighter jet they had shot down.

Flags will fly at half-mast in the Netherlands on Friday as about 2000 relatives and friends gather to mourn the victims of the disaster, while a national memorial ceremony was held in Canberra.

In Canberra, Australian Prime Minister Tony Abbott unveiled a plaque in memory of those killed, including 38 Australian citizens and residents.

Malaysian relatives also took part in an emotional memorial service in Kuala Lumpur last week, demanding justice and answers about who is responsible for the disaster.

As relatives struggle to come to terms with their grief, the focus is shifting to tracking down the perpetrators and putting them on trial.

The Netherlands has been tasked with leading the retrieval of victims' remains and investigating the cause of the crash, as well as finding and punishing possible perpetrators.

Apart from two passengers, both Dutch, the remains of all other victims have been found and positively identified.

The Dutch Safety Board is expected to release a final report into the cause of the crash during the first week of October, but has stressed it will only address the cause, not the perpetrators.

The board released a preliminary report last September saying damage to the plane's forward fuselage and cockpit section appeared to "indicate that there were impacts from a large number of high-energy objects from outside".

A criminal probe by a joint investigation team consisting of Australian, Belgian, Dutch, Malaysian and Ukrainian detectives is under way.

Dutch chief prosecutor Fred Westerbeke last month told journalists that many "persons of interest have been identified", but a dossier enabling a trial would not be ready before the end of the year at the earliest.

The UN Security Council has adopted resolution 2166, which demands those responsible "be held to account and that all states co-operate fully with efforts to establish accountability".

Malaysia, the Netherlands and others have floated the idea of a UN-backed tribunal, an idea to which veto-wielding Security Council member Russia is opposed.

Russian President Vladimir Putin on Thursday told Dutch Prime Minister Mark Rutte that establishing an international tribunal would be counter-productive.