International investigators appealed for Russian military whistleblowers to come forward after identifying the unit responsible for shooting down Malaysia Airlines Flight 17 over eastern Ukraine four years ago. Officials said that 100 people had some role in the downing of the Amsterdam to Kuala Lumpur-bound flight and appealed for Russian soldiers, their families and friends to come forward with any information to be used for a criminal prosecution. None of the 298 passengers and crew on board MH17 survived. Prosecutors working on a criminal case told a news conference that their investigations had proved without doubt that the Russian-made missile that shot down the plane came from the 53rd anti-aircraft Missile Brigade based in the city of Kursk, Russia. A chunk of missile was displayed at the briefing in the Dutch city of The Hague. The analysis of video footage, photographs and serial numbers of missile fragments has given the clearest link yet to the involvement of the Russian military. Prosecutors said they had presented their findings to Moscow but had not received a response. Russia has always denied involvement in the downing of the aircraft and blamed Ukraine for the incident. The Boeing 777 passenger jet was flying across eastern Ukraine on July 17, 2014, when it was hit by a Buk missile from territory controlled by Russia-backed rebels, using a mobile launcher brought from Russia and then swiftly returned. The international team said it was not ready to name suspects for the attack but has previously released wiretaps of conversations between two men who are heard apparently discussing the return of the missile launcher to Russia. _______________ <strong>Read more:</strong> _______________ “I can say that we are now entering the ... last phase of the investigation. When we will be ready, it is not possible to say at the moment because there is still a lot of work to do,” said Dutch prosecutor Fred Westerbeke of the Joint Investigation Team, or JIT. The JIT appealed for information from anyone who knew who gave the orders before the passenger jet was shot down. It said that witnesses could potentially be protected and given new homes outside of Russia. Investigators said their analysis allowed them to follow the missile launcher’s journey into Ukraine and traced fragments of a missile found back to a Moscow arms manufacturer where it was made in 1986. The brigade has been in the frame for the attack since 2015 when online investigative organisation Bellingcat examined videos of the Russian military convoy in Ukraine and thousands of social media profiles of Russian servicemen. Founder Eliot Higgins told <em>The National</em> that they believed the convoy had around 100 people in it with a core of 20 people directly involved in the military operation. It passed its dossier to the JIT. “I feel at this stage, the JIT probably has a lot of what it needs for the [criminal] case but it is going against the Russian Federation so it will need the best evidence possible,” he said. “It’s best they take time rather than rush to trial.” The victims came from more than 30 different countries and included 196 Dutch, 42 Malaysian and 27 Australian citizens. The investigation team draws together investigators from five countries and any identified suspects would stand trial in a Dutch court. Questions remain over whether Russia would allow any of its citizens to leave the country. It follows Moscow's refusal to allow British investigators to quiz key suspects in the 2006 London murder of Russian dissident Alexander Litvinenko and the diplomatic crisis sparked by the attempted assassination of former spy Sergei Skripal in the UK earlier this year.