A key suspect in the downing of Malaysia Airlines Flight 17 was detained on unrelated charges in eastern Ukraine around the time the murder trial against the MH17 suspects started in the Netherlands this spring, BBC Russia reported Thursday.

Former field commander Leonid Kharchenko, 47, is the only Ukrainian passport-holder among four suspects named by the Dutch-led investigation into the tragedy that killed all 298 people on board flight MH17 in July 2014. The other three are Russian nationals who, like Kharchenko, are expected to be tried in absentia.

Leonid Kharchenko Screenshot Youtube

Pro-Russian authorities in the self-proclaimed Donetsk People’s Republic arrested Kharchenko near his home on March 11, BBC Russia cited an unnamed former commander who had served with Kharchenko as saying. He was reportedly charged with illegal possession of firearms and an illegal search.

The MH17 trial began on March 9.

Former fellow soldiers say they believe that the pro-Russian authorities pressed what they call “ridiculous” charges against Kharchenko in order to shield him from a kidnapping attempt by Ukraine. 

Ukrainian authorities, who are engaged in a six-year war with Russian-backed separatists in the country’s east, charged Kharchenko in 2015 with creating a terrorist group.

Ukrainian security services kidnapped a key MH17 witness last year, only for him to be handed over to Russia as part of a high-profile prisoner swap.

“Kharchenko lived a quiet life in Donetsk and didn’t suspect that this could happen to him,” BBC Russia quoted an unnamed former fellow soldier as saying. “Perhaps they’re guarding him in this cruel way, but it’s a very strange way of securing a person.”

Kharchenko is reportedly being held in a Donetsk justice ministry detention center. Authorities extended his arrest by two months last Friday, according to BBC Russia.

Dutch-led prosecutors accuse Kharchenko and the three Russian suspects of playing central roles in transporting and launching the Buk missile system that brought down the plane.

Russia denies any role in the downing of MH17.

Judges at a March hearing in the Netherlands adjourned the MH17 trial until June 8 to give defense lawyers more time to prepare.