Australian Federal Police (AFP) have warned an Australian citizen to return items he collected from the MH17 crash site near the Ukraine-Russian border.
First generation Australian-Ukrainian Demjin Doroschenko was in the region working as a freelance journalist when MH17 was shot down.
The plane was blown out of the sky in July 2014, killing 298 people, including two New Zealanders.
Many of those on board the plane were Dutch and the Dutch Safety Board said last year the plane was shot down by a Russian-made Buk missile,
Mr Doroschenko, 45, said he was one of the first on the scene and formed the self-proclaimed MH17 Donbass Recovery Team.
He collected hundreds of pieces of evidence for "safekeeping and out of reach of the forces of the Russian Federation", he said.
"It needs to be rescued or otherwise the Russians will appropriate any other pieces that they can use in their case against the Joint Investigation Team [JIT]," he said.
He claimed he had already handed some items over to authorities in Kiev but still had possession of dozens more.
Mr Doroschenko, who is still in Ukraine, said he recently offered the items to AFP and the Dutch-led JIT, and asked to be paid for transportation costs but they refused.
AFP said it was aware the personal belongings of Australian passengers had been taken from the site and it had issued a warning to Doroschenko.
"Items recovered from the MH17 crash site should not be used to obtain a profit or benefit," an AFP spokesman said.
"To do so only harms the families of victims who are looking for a resolution that could be provided by investigators having access to all of the crash site evidence.
"The AFP and JIT are aware that Mr Doroschenko may have visited the MH17 crash site and have provided him with a process of how he can provide those items to the JIT.
"Any criminal offences applicable to possession of property belonging to victims of MH17 (including Malaysia Airlines) will be the jurisdiction of Ukraine or Malaysia."
Doroschenko said he did not want to follow the return protocol as it involved handing items back to local mayors who he claimed were in collaboration with Russian forces.
In January, he was arrested by Ukrainian border officials and questioned about his work in the area but later released.
One of the hundreds of items he claims to have is a backpack belonging to Toowoomba victim Jill Guard.
A Guard family spokesman urged anyone with personal belongings to hand them back and asked for their privacy to be respected.
"Anyone trying to make a profit is not helpful and I encourage them to return items without any strings attached," the spokesman said.