WASHINGTON: A mysterious man wanted in connection with the deadly downing of Malaysia Air Flight 17 over eastern Ukraine in 2014 appears to be a high-level Russian military intelligence officer, an investigation by a team of reporting outlets has found.

The reporting team, made up of McClatchy and investigative websites Bellingcat in Great Britain and the Insider in Moscow, identified the man, previously known only by his call sign Orion, as Oleg Vladimirovich Ivannikov.

Information about Orion has been long sought by a five-nation Joint Investigation Team conducting a criminal probe of the tragedy.

On Thursday that team, citing several unique markers on photographs of a Russian BUK rocket launcher taken in the border area near the wreck, formally accused a specific division of the Russian military of bringing down the passenger aircraft, killing all 298 aboard. The head of Holland’s National Investigation Service called on witnesses to help identify those who gave orders.

Russia’s Defense Ministry said that “Russian BUKs never crossed Ukraine border.”

The July 17, 2014, missile strike on a plane full of passengers from 17 nations flying above 30,000 feet from Amsterdam to the Malaysian capital of Kuala Lumpur shocked the world. Ukrainian leaders blamed Russia or ethnic Russian separatists.

Since the five-nation team hopes to bring criminal charges, identifying the chain of command in the plane’s downing is vital. Made up of representatives from the Netherlands, Ukraine, Malaysia, Belgium and Australia, the team did not know Orion’s identity on Thursday when pinning the missile strike on Russia.

Orion was captured on cellphone intercepts with a semiretired three-star Russian major general who used the call sign Delfin on the day of and in the days after the plane’s downing. A report published last December by the collaborating news outlets identified Nikolai Federovich Tkachev as Delfin, the general and one of two senior officers who oversaw the movements of the BUK launcher.

The day after the plane’s downing, the Ukrainian security service published an intercept dated two days before the incident in which Orion explicitly says, “We got a BUK now ... so we start shooting the hell out of their planes.”

When a member of the reporting team called Ivannikov for comment, a relative said to call back later in the day. But Ivannikov refused to come to the phone later.

Reporting partners have determined with a high degree of probability that Orion is the Russian citizen Ivannikov, born in 1967 in what was East Germany, the son of a decorated Soviet major general.

Ivannikov’s true name has remained hidden in part because, like other Russian officers in the GRU military intelligence unit, he does not operate under his true identity.

Instead, Ivannikov appears to have been using an alternate identity: Andrey Ivanovich Laptev. Under that assumed name, he helped lead an uprising of ethnic Russians in South Ossetia, a breakaway region of the former Soviet republic of Georgia. He was effectively part of what would become a private Russian shadow army that later fought in Ukraine and even later in Syria, where they took a strike in February from U.S. warplanes.