Russian state television has broadcast what it says are satellite images of a MiG-29 fighter jet flying near the Malaysia Airlines jet that was shot down over eastern Ukraine in July.
The report on Saturday quoted Ivan Andrijewski, vice president of the Russian union of engineers, as saying the images presumably came from a British or a US spy satellite.
Moscow drew wide condemnation over the July 17 flight MH17, which experts said was brought down by an explosion consistent with a surface-to-air missile.
Pro-Russian separatists are suspected of firing a missile that brought down the jet, killing 298 people. The separatists deny firing at the jet.
But Russia has said the airliner was shot down by a fighter jet, allegedly belonging to the Ukrainian government, and the television report suggested that the satellite images proved that assertion.
Investigators in the Netherlands have uncovered no evidence that another aircraft flew near the Boeing 777 passenger jet en route from Amsterdam to Kuala Lumpur.
Russian state television described its story as a "sensation" airing just as the G20 summit opens in Brisbane Australia.
Australian Prime Minister Tony Abbott was expected to take Russian President Vladimir Putin to task about the tragedy. Russian state television said its revelation was important for the confrontation between the two leaders.
Moscow already has drawn condemnation from Canberra over the downing of the jet. There were 38 Australians among the dead. Abbott has placed the blame for the tragedy on Putin because Russia supports the separatists in eastern Ukraine and has demanded the Russian leader apologise during the summit.
Russia has demanded an independent investigation that considers other variations of what might have happened.
The tragedy occurred four months after Russia's annexation of the Crimean peninsula, and as pro-Russian separatists in eastern Ukraine took up arms against the government in Kiev.
The United States and European Union, among the first to respond with sanctions on Moscow, accused Putin of obstructing Dutch-led efforts to carry out an investigation into the MH17 crash.
Meanwhile, Dutch experts will be able to search for more pieces of MH17 under an agreement reached between pro-Russian separatists and Dutch representatives, a Dutch newspaper reports.
The Dutch investigators will be allowed to return to the region controlled by the separatists under the agreement reached in negotiations overseen by the Organisation for Security and Co-operation in Europe, the Dutch newspaper Volkskrant reported late on Friday, quoting the Justice Ministry in The Hague.
Many pieces of MH17 wreckage lie in the area controlled by the separatists, which has made their recovery especially difficult.
Earlier this month experts were still recovering human remains and pieces of the jet.