Investigators say Putin likely approved the supply of the missile system that brought down Flight MH17.

There are “strong indications” that President Vladimir V. Putin decided to supply the antiaircraft missile system that Russia-backed separatists used to shoot down a Malaysia Airlines jet above eastern Ukraine in 2014, a Dutch-led international team found.

But the team said on Wednesday that it had suspended its criminal investigation because of insufficient evidence and immunity privileges that prevent new prosecutions in the crash of Flight MH17, which killed all 298 people aboard.

The investigators noted that no evidence suggests that Mr. Putin ordered that the aircraft be shot down and that he was, in any case, protected from prosecution under Dutch law because he enjoys immunity as a head of state.

“The investigation has now reached its limits,” Dutch prosecutor Digna van Boetzelaer said at a news conference. “All leads have been exhausted.”

The announcement came nearly three months after a Dutch court convicted three men with ties to the Russian security services for their roles in shooting down the plane while they were part of separatist forces in eastern Ukraine.

The international team of investigators continued to look into who was responsible for providing the weapons. On Wednesday, investigators presented new evidence, including cellphone intercepts that showed ties between the Russian military and the separatists, and suggested that delivery of the missile system was delayed because Mr. Putin had been participating in a World War II commemoration in France.

“He’s the only one who makes the decision, nobody else,” the audio intercept said. The intercept appeared to confirm that the surface-to-air missile used to shoot down the plane was trucked in from Russia at the request of the separatists.

Ms. van Boetzelaer said that “secondhand information was obtained about the possible involvement of three current or former officers” of the Russian military. But the investigation team could not establish that with certainty, nor could it specify who gave the order to separatist forces to fire the missile.

The findings “do not provide sufficient ground for prosecution,” Ms. van Boetzelaer said, “because the evidence that has been gathered is not strong enough to be lawful and convincing.”

She added that Russian military members “may be able to claim combatant immunity,” a rule in international law that bars the prosecution of members of the armed forces of a state, except for war crimes.

Russia-backed separatists invaded eastern Ukraine in 2014, beginning a long-simmering conflict that predated Moscow’s full-scale invasion in February 2022. The crash of MH17 in July 2014 was by far the biggest loss of civilian life in the conflictup to that point. Most of the victims were Dutch; the flight also carried passengers from Australia, Britain, Malaysia and other countries.

Many victims’ families have drawn a direct connection between the crash and the current war, suggesting that the West’s failure to strongly punish Moscow in 2014 helped enable its full-scale invasion.

The Kremlin did not immediately respond to the statement by investigators. In November,Russia’s Foreign Ministry called the trial in which the three men were convicted politically motivated.