The Kyiv Court of Appeal handed down the ruling on September 5, saying Tsemakh should be released immediately on his own recognizance.

A Ukrainian national, Tsemakh reportedly oversaw an air-defense unit among Russia-backed separatists in a town near where the jet came down.

An international Dutch-led investigation has already concluded that the commercial airliner was shot down by a Russian-made Buk missile that was fired in territory held by Moscow-backed separatists and reiterated on September 5 that it would like to question Tsemakh over the tragedy.

“We would have liked to have speak to him and it’s going to be difficult now,” Brechtje van de Moosdijk, a spokeswoman for the Joint Investigation Team, told RFE/RL by telephone. “We would rather have him in Ukraine so we could speak to him.”

The ruling comes amid talks between Moscow and Kyiv on a prisoner swap that unconfirmed reports have said includes Tsemakh.

Speaking in the eastern Russian city of Vladivostok on September 5, Putin said an agreement on a prisoner exchange “is near.”

"We are finalizing our negotiations on an exchange. I believe it will be rather large-scale, and that would be a good step forward towards normalization [of relations with Ukraine]," Putin said while attending the Eastern Economic Forum.

Sailors Detained

Kyiv is seeking the return of 24 sailors detained by Russia last year off annexed Crimea, as well as filmmaker Oleh Sentsov and others whom rights groups and the government in Kyiv say are “political prisoners” in Russia.

Tsemakh’s release also comes a day after a group of 40 members of the European Parliament wrote a letter urging Ukrainian President Volodymyr Zelenskiy not to include the suspect in any deal.

The letter said Tsemakh is a “key suspect” in shooting down of flight MH17, which killed all 298 people on board.

“While we understand the context within which such negotiations are taking place and the diplomatic efforts by the Ukrainian authorities to this end, Mr. Tsemakh is a suspect in the criminal investigation related to the downing of flight MH17 and his availability and testimony before the Joint Investigation Team is thus of the utmost importance for an effective prosecution by the countries involved,” the letter states.

Investigators maintain the missile system used in down MH17 belonged to a Russian military unit and that it was transported from and back to Russia after being used.

Three Russians and a Ukrainian were indicted over the downing of MH17, and court proceedings in The Netherlands are scheduled for March. But the four suspects most likely will be tried in absentia.

Russia called the charges against its citizens “absolutely unfounded” and said the investigators based their findings on “dubious sources of information,” accusing them of rejecting evidence the Kremlin has provided.

Moscow has also aired its own theories on the shoot-down but never provided solid evidence.

Tsemakh is not one of the four indicted.

"The very fact that Russia came up with such a strict condition [for a prisoner swap] -- that itself incriminates the Kremlin because what does a Ukrainian separatist who has never even been a Russian citizen and has never worked in Russia have to do with it? And why have they turned him into the key link of the entire chain of the swap arrangement at the very last moment?" asked Christo Grozev, a member of an independent Bellingcat research organization which participated in the investigation of the downing of MH17.

"This may be a blow to the legitimacy of this [Dutch-led] court case from the point of view of the optics, but the court will have enough objective evidence in the case for the judge to issue an objective verdict. I think Ukraine would do well to expose all the details of the swap negotiations so that the court could also take that into account when making the decision," he added.

The Ukrainian Security Service (SBU) apprehended him on June 27 in the Donetsk regional city of Snizhne, which is held by Moscow-backed separatists and is 20 kilometers from the Russian border.

According to the Dutch-led investigation, the Buk missile was fired six kilometers south of Snizhne.

TV footage obtained by Current Time showed Tsemakh claiming that he was in charge of an antiaircraft unit and that he helped hide the missile system in July 2014.

He also shows the interviewer where the civilian airliner fell.