Two unidentified aircraft were seen soaring above Ukraines embattled Donetsk region earlier this month when one suddenly released a missile, blasting the other out of the sky in a violent explosion that was caught on camera.
Initial theories suggested the video captured a routine air defence mission in which a Ukrainian jet followed and downed a low-end drone launched by Moscows troops - a scenario that has played out countless times since the February 2022 invasion.
But the news that Ukraines air force was not involved triggered wild speculation, with analysts and war observers on both sides racing to uncover the true story behind the mysterious incident.
Russias defence ministry never commented on what really happened.
Before long, respected war blogging channels and sources on both sides of the conflict confirmed what Ukraines supporters had hoped - that Vladimir Putins air force was compelled to destroy one of its own prized assets.
It is believed that a Su-57 jet, arguably Russias most advanced fighter aircraft, shot down a cutting-edge S-70 Hunter drone that had malfunctioned and was drifting deeper into territory held by Ukraine.
And although the pilot was somewhat successful in keeping the top-spec military kit out of Kyivs hands, huge chunks of the craft still landed in Ukraine and are now being pulled apart by military scientists and engineers.
Here, MailOnline breaks down what we know about the Kremlins frighteningly capable drone - and the treasures that could be gleaned from its wreckage.
It is believed that a Su-57 jet, arguably Russias most advanced fighter aircraft, shot down a cutting-edge S-70 Hunter drone that had malfunctioned and was drifting deeper into territory held by Ukraine
The wreckage of the Okhotnik is seen lying on the ground after impacting a small building in Kostyantynivka
Ukrainian service members inspect parts of a Russian aerial vehicle, which local authorities assume to be a newest heavy unmanned aerial vehicle S-70 Okhotnik
Two unidentified aircraft were seen soaring above Ukraines embattled Donetsk region earlier this month when one suddenly released a missile, blasting the other out of the sky in a violent explosion that was caught on camera
The drone fell out of the sky and landed in a Ukrainian controlled part of Donetsk
A Sukhoi S-70 Okhotnik heavy unmanned combat aerial vehicle after the first joint flight with a Sukhoi Su-57 jet fighter in 2019. The drones design and capabilities are said to have been significantly upgraded in the past 5 years
The Hunter drone is controlled by the pilot aboard a Su-57 Felon - one of Russias most advanced jets
The Sukhoi S-70 Okhotnik-B, or Hunter, is set to be the cornerstone of Russias advanced unmanned combat aerial vehicle (UCAV) arsenal in the coming years.
Its silhouette has been likened to that of the US RQ-170 drone - one of Americas most capable UAVs built by Lockheed Martin, as well as the instantly recognisable Northrop B-2 stealth bomber.
The product of a joint development project between two of Russias most feted aviation design bureaus, Sukhoi and MiG, the Hunter was first proposed as early as 2009, but prototypes did not emerge until a decade later.
It performed successful test flights in 2019, footage of which was triumphantly broadcast by Russias defence ministry, but despite its promise, the Hunters production was marred by delays and setbacks amid demands for more powerful engines and upgraded electronic systems.
Now though, the drone is set to enter serialised production after senior officials at Russias state defence industrial corporation Rostec declared earlier this year it would be ready for combat service with air force units in the second half of 2024.
Of course, the Hunters exact capabilities remain a mystery, but footage of the vehicle and publicly available information have led analysts to believe the UAV could prove a highly effective asset for the Russian air force in Ukraine.
Its AL-41F1 engine propels it to speeds of 1,400 kilometres per hour, or Mach 1.17, and it is believed the drone can carry between three and five tons of ordnance, though this is not proven.
It has however demonstrated a capability to deploy 500kg bombs from an internal payload bay.
This makes it a serious aerial threat, particularly given that its stealthy profile minimises its radar signature, thereby increasing the likelihood that the unmanned craft could slip by air defences despite its massive 19-metre wingspan.
The Hunter operates as a loyal wingman to Russias Su-57 5th generation fighter, allowing the jets pilot to control the drone remotely through secure datalinks.
In theory, the pilot can guide the drone, assigning it tasks like reconnaissance, target acquisition, or precision strikes while keeping the far more expensive jet at a safer distance.
The drone can also operate semi-autonomously, handling navigation and target engagement on its own when necessary - and some sources claim a fleet of five drones can be controlled by a single Su-57.
The fact the Su-57 pilot was forced to shoot down their drone suggests that Russias defence manufacturers have not yet managed to iron out all of the vehicles bugs, with several Russian sources telling war blogging channels the asset was undergoing a test flight when it malfunctioned, rather than a combat mission.
It also implies deep concern in the Russian military over the potential exposure of its technological secrets to Kyiv, and by extension, its Western allies.
A former Sukhoi developer told Russian news outlet Mash that Russias air force operates a strict protocol by which pilots must destroy any new technology to prevent it falling into enemy hands.
In such situations, the most important thing is the friend-or-foe codes, he said, referring to the software that allows militaries to identify whether an object belongs to allied forces or the enemy.
If theres a chance these could be captured, pilots must eliminate the systems responsible... no one wants those codes in enemy hands.
Parts of a Russian aerial vehicle, which local authorities assume to be a newest heavy unmanned aerial vehicle S-70 Okhotnik is seen in residential area of the town of Kostintynivka after it was shot down
A former Sukhoi developer told Russian news outlet Mash that Russias air force operates a strict protocol by which pilots must destroy any new technology to prevent it falling into enemy hands
A Ukrainian scene investigator examines the wreckage of an allegedly downed Russian unmanned combat aerial vehicle S-70 Hunter drone, in Kostyantynivka
The Hunter operates as a loyal wingman to Russias Su-57 5th generation fighter (pictured), allowing the jets pilot to control the drone remotely through secure datalinks
The first joint flight of a Sukhoi S-70 Okhotnik heavy unmanned combat aerial vehicle and a Sukhoi Su-57 jet fighter is pictured in 2019
A Sukhoi S-70 Okhotnik heavy unmanned combat aerial vehicle after the first joint flight with a Sukhoi Su-57 jet fighter
Experts from Russias Special Technology Centre - a major manufacturer of unmanned aerial vehicles, electronic warfare systems and communication systems for Putins forces - also analysed the crash footage.
They concluded that the risk of intelligence leaks to Ukraine in the wake of the crash is low, claiming that much of the critical technology aboard the drone likely burned up in the wreckage or was damaged beyond repair.
Those who stumbled upon the wreckage didnt even know what they had found, which played in Russias favour. Only the fuselage remains intact - nothing that could give away the secrets of its design.
But the Sukhoi developer who spoke to Mash was far more concerned, warning that Ukrainian and NATO countries could gain valuable insight into Russias drone programme and the capabilities of the Hunter if its electronic warfare systems survived.
Although a significant portion of the drone was destroyed in the missile strike and subsequent impact, images out of Donetsk showed that large chunks of drone, including the majority of one wing and a considerable section of the fuselage, were well preserved.
Professor Justin Bronk, senior research fellow for airpower and technology at the Royal United Services Institute, described the incident as a stunningly embarrassing failure for Russia.
It really does look like the VKS (Russian aerospace forces) shot down its own Su-70 Okhotnik-B heavy combat UAV prototype in a friendly fire incident! he said in a post on X.
A stunningly embarrassing failure and one which also reveals they must have been conducting test flights near the front; possibly testing sensors or (command-and-control links).