An international crime team investigating the downing of flight MH17 over eastern Ukraine last July has produced a video urging witnesses who saw a missile launcher to come forward.
Describing the Buk launcher as one of the main scenarios, the team says it can provide witnesses with protection.
All 298 people on the flight from Amsterdam to Kuala Lumpur were killed.
A preliminary Dutch report said the plane broke up after being penetrated by “high-velocity objects”.
However, the Dutch Safety Board did not specify the involvement of a Russian-made Buk launcher and its final report will not be released until October.
The Ukrainian government and the West have accused the Russian authorities of supplying the separatists with the Buk missile launcher, providing witness statements and photographs.
But the Kremlin has argued that Ukrainian forces were responsible for the Malaysia Airlines crash.
Dutch broadcaster RTL said this month it had new evidence from a metal fragment found at the crash site that the plane was hit by a surface-to-air missile, launched from a Russian-made Buk.
In the video, investigators involved in the criminal investigation show photographs and footage of the launcher being moved around areas of eastern Ukraine held by pro-Russian rebels, before and after the plane was brought down on 17 July, and the following day when the launcher is alleged to have crossed the border into Russia.
Three phone intercepts are also produced, including two that have not been made public until now.
Dutch prosecutors say the appeal for witnesses does not mean that the Buk missile launcher is seen as the definitive scenario, as it is too soon to draw conclusions.
In the first conversation, separatists are heard at 09:08 on 17 July, several hours before the disaster.
A man in Donetsk asks where the Buk should be taken. “It needs to be unloaded somewhere in order to hide it,” he is heard saying.
In the second conversation, some five hours after the plane is brought down, a crew member from the Buk has apparently become lost and two separatists are discussing how he can be reunited with his colleagues.
A video is then produced appearing to show the launcher being transported on the back of a Volvo low-loader.
In the final conversation, at around 08:00 on 18 July, a phone intercept suggests the Buk launcher is already over the border in Russia and one of the speakers refers to a “mess” and a “disaster”.
298 victims from 10 countries
- Netherlands: 196
- Malaysia: 42
- Australia: 27
- Indonesia: 11
- UK: 10
- Belgium: 4
- Germany: 3
- Philippines: 3
- Canada: 1
- New Zealand: 1
The 298 who died