Vladimir Tsemakh is in custody after being seized by Ukrainian special forces.
Tsemakh, 58, was detained by a snatch squad at his home in Snizhne, a town in a breakaway region of eastern Ukraine that is backed by Russia, on June 27.
He is reported to have been injected with a tranquilliser, put into a wheelchair and smuggled nearly 50km across separatist-held territory into government-controlled Ukraine, The Australian newspaper reported today.
It said leaked photographs showed him in custody with a bandaged head.
Tsemakh was not among the four suspects named by the Dutch-led Joint Investigating Team (JIT) probing the tragedy.
However, he is believed to have important information about the Buk’s movements.
The newsaper quoted Ukrainian military journalist Yuriy Butuso as saying: “Tsemakh’s testimony at international courts could lead to serious consequences for Russian President Vladimir Putin and the Russian Federation.”
The news report said Ukraine has charged Tsemakh with membership of a terrorist group, an offence that carries a 15-year prison sentence. More serious allegations may follow.
Aric Toler, who has researched the Buk’s journey from Kursk in central Russia to the area around Snizhne, said Tsemakh is an important witness.
“He wasn’t the guy who fired the missile or anything like that, but he would have definitely had some knowledge of the Buk’s deployment.
“At most, he directly assisted with hiding the Buk, was aware of its deployment and knows exactly who was in the Buk crew.”
The four suspects in the shooting down of MH17 all have ties to the Russian military. They are believed to be living in Russia or in separatist-held regions of eastern Ukraine, the report added.
The Kremlin refuses to extradite Russian citizens to face criminal charges so there is little chance any of the men will appear in court when their trial starts in The Netherlands in March, The Australian added.
All 298 people aboard, including 38 Australian citizens and residents, died when the missile tore into the Boeing 777 en route from Amsterdam to Kuala Lumpur. It is believed that separatist forces mistook it for a Ukrainian warplane.
The Dutch-led joint investigative team charged three Russians and one Ukrainian last month with transporting the missile system into Ukraine on the day of the attack. It said the Buk was supplied by Russia’s 53rd air defence brigade.
President Vladimir Putin denies any Russian involvement.