A British tank given to Ukraine was destroyed during fighting against Russian invasion forces, according to the PA news agency.
A defense source said it was possibly the first time a Challenger 2 had been disabled by enemy action.
The last time one of the heavily armored fighting vehicles was destroyed is believed to have been during friendly fire in Iraq in 2003.
Footage shared widely on social media shows one of the 14 tanks the UK gave to Kiev in January on the side of a road with thick gray smoke and fire billowing from it.
It is not clear how the tank was destroyed, but it is understood that the Ukrainian crew in the tank survived the attack.
The video appears to have been taken from a car containing Ukrainian armed forces personnel trying to flee the fighting.
A defense source told the PA: “This underlines the quality of the kit we are giving to Ukraine.
“On the tanks that Ukraine had before Western support, the chances of the crew surviving unscathed were slim to none.”
The Ministry of Defense said it would not comment.
The location has not been confirmed, but reports say the video was taken on the southern front of Zaporizhzhia, where the Ukrainian counter-offensive has been focused.
Since the counteroffensive began about three months ago, Ukraine has advanced 4.3 miles into the Zaporizhzhia region, Ukrainian officials claim.
The troops broke through dense Russian fortifications last week to retake the village of Robotyne.
This was Ukraine's first major tactical victory in this part of the country.
The Institute for the Study of War, a think tank, said on Tuesday that Ukrainian light infantry had advanced beyond some of the anti-tank ditches and dense minefields that make up Russia's layered defenses in Zaporizhia.
However, he said he was unable to say the defense was fully breached because no Ukrainian heavy armor was seen in the area.
Ukraine has adjusted its counterattack tactics in recent weeks, shifting from attempts to force its way through Russian lines using Western armor to better-planned tactical attacks that are yielding incremental gains, according to the Royal United Services Institute, a think tank. .
But even after the change, progress remains slow, the think tank said, with 700 to 1,200 meters being gained every five days.
Prime Minister Rishi Sunak signed off on the delivery of 14 Challenger 2 tanks to Ukrainian President Volodymyr Zelensky earlier this year, ahead of the one-year anniversary of the conflict in February, as he sought to bolster Kiev's efforts to push back Russian troops.
The move opened the door to other Western nations delivering tanks to Ukraine, with Leopard 2 tanks donated by Germany and other European countries, while the US donated the Abrams.
Defense sources said the war in Ukraine was the first time the Challenger 2 was tested against modern military equipment.