The Reporters Without Borders (RSF) shared its investigation.
"Analysis of crime scene photographs and seized evidence clearly indicates the execution, which may have been preceded by interrogation or even torture," said RSF Secretary General Christophe Deloir.
RSF Investigator Arno Froje and French military photojournalist Patrick Chauvel, who worked with Levin in the Donbas in late February, spent more than a week gathering evidence and clues in Ukraine about the circumstances of Levin's death.
On March 10, the photojournalist lost his drone in the woods near Moshchun, trying to obtain footage of Russia's military invasion of the area. When he returned to these forests three days later, Russian forces already occupied part of the forest.
The bodies of Levin and Chernyshov were found on April 1 in a forest near the village of Moshchun, 20 km north of Kyiv. Two men were killed on March 13.
Accompanied by the security forces of Ukraine, the RSF managed to determine the crime scene. The Levin's charred Ford Maverick was still there.
Several bullets were found at the scene, as well as documents proving the identity of Chernyshov, a serviceman who was with Levin, and found 14 bullets in his car.
Investigators believe Levin was probably killed by one or two shots at close range. In the last phase of the RSF-initiated search, metal detectors found a bullet that probably hit Levin. Chernyshov could be burned alive.
The RSF notes that Levin and Chernyshov could have been killed by troops of the 106th Airborne Division or Russian special forces. The 106th Division is commanded by Colonel Volodymyr Seliverstov.
The RSF report suggests that before Levin and Chernyshov were executed, the Russians may have used torture to interrogate them.
The Deputy Prosecutor General of Ukraine, the Head of the Department for Investigation of Crimes against the Media and the Head of the Kyiv regional Prosecutor's Office met the RSF representatives.
Arnaud Frogge was officially deposed by the Ukrainian Security Service as a witness in Kyiv on June 1. The RSF handed over nine pieces of evidence gathered on the ground and a flash drive with dozens of photos from the crime scene taken by Patrick Shovel.