Relatives of victims of flight MH17 that was shot down over Ukraine a year ago joined emotional memorials on Friday as calls mounted for a UN-backed tribunal to prosecute those responsible for the tragedy.

All 298 passengers and crew -- the majority Dutch -- died on July 17 last year when the Malaysia Airlines Boeing 777, on a flight from Amsterdam to Kuala Lumpur, was downed over rebel-held east Ukraine during heavy fighting between Kiev's armed 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.

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

As the bereaved marked the sombre anniversary around the world, Ukraine's President Petro Poroshenko said it was a "moral duty" to punish the "murderers" of the MH17 victims.

On Friday, Sydney's Daily Telegraph newspaper 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 insurgent stronghold in Donetsk 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.



Mourning the dead


Flags flew at half-mast in the Netherlands as some 2,000 relatives and friends gathered to mourn the victims of the disaster, while a national memorial ceremony was held in Canberra.

Dutch Prime Minister Mark Rutte told the NOS public broadcaster ahead of the service: "I still think about it every day."

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

"Today we remember our dead, we thank those who brought them home. But most of all, we acknowledge the suffering of the bereaved," he told the crowd, which included 120 relatives of those who perished.

During the emotional ceremony, tears flowed as photographs of the smiling faces of victims were flashed up on to big screens followed by the word "remember".

Australian Paul Guard, who lost his parents Roger and Jill, made the journey to the Australian capital with nine other family members.

"It will be a difficult day but hopefully a useful part of the healing process," he told reporters ahead of the service.

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.



Criminal probe


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 underway.

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

Britain, 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.

The European Union said it supported efforts to set up a tribunal, with the bloc's foreign policy chief Federica Mogherini saying that "those directly or indirectly responsible for the downing of MH17 must be held accountable and brought to justice".

Relatives of some MH17 crash victims on Wednesday filed a nearly $900 million suit in the United States against a one-time leader of the Ukrainian rebels over the disaster.

The writ alleges that Igor Strelkov, a Russian also known as Igor Girkin, was acting with the "actual or apparent" authority of President Vladimir Putin's government when the plane was shot down.