At the end of September, a Telegram channel known for its network of Russian intelligence sources reported that a Black Sea fleet submarine had run into serious technical problems while on a mission off Gibraltar, in the Mediterranean. The Novorossiysk submarine was at risk of exploding, it said, and according to online sleuths, later surfaced, giving away its location. But the question remains, what was a Russian sub even doing there? This is what we know so far:

The news that a short-rangeRussianstealth hunter was circling in theStrait of Gibraltarfirst came to public attention on September 27. The anti-KremlinTelegramchannelVChK-OGPU reportedthat the 74-metre-long Kilo-class Novorossiysk currently on combat duty in the Mediterranean had experienced a technical failure, and that fuel was leaking into the bilge, the very bottom of the vessel hull.

The submarine has neither the spare parts nor the qualified specialists onboard to fix the malfunction, VChK-OGPU wrote, and warned that the sub now poses an explosion hazard.

An alleged September 26sightingof a submarine surfacing in the Strait ofGibraltarappeared to confirm its location.According to online sleuths, aUS Navy maritime patrol planealso flew over the area where the submarine was spotted for several days in a row.

Neither Russian authorities nor state-controlled media have confirmed the subs presence in the Mediterranean.

FRANCE 24 takes a closer look at why theNovorossiysk was in one of the busiest and most strategic naval corridors in the world.

What kind of submarine is it?

The Novorossiysk is 74 metres long and can carry a crew of around 50 people. Alexandre Vautravers, a defence expert and editor-in-chief of the Swiss Military Review, said the diesel-electric sub is relatively modern.

It was developed in the 1980s.Itdoesnt belong to thesubmarinesfrom the 1940s and 1950s which were frequently subject to breakdowns.

The Kilo-class a name given to these types of Soviet-era submarines byNATOisnt very sophisticated, he said.

It was designed to be produced in large numbers rather than to give the Russian fleet a cutting edge. Russia has also exported a lot of these submarines because they dont contain any secret technology.

The Novorossiysk belongs to one of the more recent Kilo-class models, and was put into service in August 2014. Itjoined Russias Black Sea fleetin September 2024.

Like other submarines in its category, the Novorossiysksmain purpose is to operate in coastal waters where the seas are not too deep, Vautravers explained.

It is equipped with torpedoes, however, which would make a potential fire onboard particularly dangerous, and is capable of carrying Kalibr cruise missiles the Russian equivalent of US Tomahawk missiles. It can also deploy naval mines.

Prior to its sighting near Gibraltar, the Novorossiysk was spotted off the French coast of Brittany in 2022, prompting authorities there to dispatch a vessel to follow it. In July this year, it was spotted again this time in theEnglish Channeland was subsequently tailed by the British navy.

What wastheNovorossiyskdoing in the Strait of Gibraltar?

Although VChK-OGPU claims the Novorossiysk was on a combat mission, it does not necessarily mean it was intending to target British positions on Gibraltar, or anything else for that matter.

Most often, these types of missions are about intelligence gathering or the discreet transport of personnel and equipment," Vautravers said.

The Strait of Gibraltar is perfect for these types of covert operations. It is the only maritime gateway between the Atlantic and the Mediterranean, and all vessels passing through it are closely monitored.

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On top of that, Russia has a tradition of maintaining a naval presence in the Mediterranean, explained Basil Germond, an international security expert and maritime affairs at Lancaster University.

Its long-term naval deployments to achieve political, economic and strategic objectives by projecting its military influence in a region, he said.

He described Russias ability to exert influence in the Mediterranean as very limited at the moment, however, pointing to the war in Ukraine and its recent loss of the naval base in Tartus, Syria.

It was a major setback for the Russian navy, he said.

This means that the Novorossiysk is likely one of the few Russian warships still operating in the Mediterranean, showcasing Moscows waning influential power in the region.

How serious is the damage to Novorossiysk?

With no official confirmation from the Kremlin, the extent of the reported damage or whether there is any at all remains unclear.

But in line with VChK-OGPUs claim that Novorossiysk lacked both spare parts and competent staff to repair the potentially explosive fuel leak, Germond noted that: Russian warships are known to be poorly maintained, with crews that are untrained to handle these types of situations."

Russias war efforts in Ukraine have resulted in even less spare parts and specialised staff being available.

Vautravers underscored that the Novorossiysk is not a nuclear sub. So the environmental and safety impact of an explosion [of the ship itself] would be limited. The risks, he said, are rather tied to the type of arms that might be onboard. Mines and missiles would make the situation much more dangerous.

Another challenge the crew faces, Germond said, is that Russia has no ports nearby and the Novorossiysk would have to be towed all the way to Saint Petersburg to be repaired. Considering the current climate, Russia definitely wont ask a NATO country for help if it isnt able to resolve the problem by itself, he said.

One of the few remaining solutions, a source told the VChK-OGPU channel, would be for the crew members to start pumping out the bilge themselves, into the sea.

This article was adapted from theoriginalin French by Louise Nordstrom.

Originally published on France24