The British military has discovered Russian sensor devices in its territorial waters that it believes are designed to spy on UK nuclear submarines, The Sunday Times reported in a major investigation, citing data from the country's Ministry of Defence. The authorities' suspicions go further: superyachts owned by Russian billionaires and drones targeting underwater communications cables may be involved in the spying activity.

The Sunday Times investigation is based on dozens of interviews with senior military officials, former defence officials and security experts. The reporters also visited the deep-sea surveillance vessel RFA Proteus, which is involved in the Royal Navy’s operations. According to sources, the current maritime standoff between Russia and the UK resembles a Cold War technological duel, comparable to the space race between the USSR and the US. The main difference is the secrecy and sophistication of modern methods that threaten key British infrastructure.

Some of the discovered sensors fell into the hands of the military by accident - they washed up on the coast. Other devices were found in recent years by minesweepers of the Royal Navy. As the publication notes, these finds have caused serious concern in London, as they may be part of a system for tracking the movements of British submarines equipped with nuclear weapons. Information about the sensors has long remained classified, emphasizing their importance for national security. Suspicions against the superyachts of Russian oligarchs arose due to their frequent appearance near strategically important areas where underwater cables and military vessels pass.

The British authorities see these incidents as part of a hybrid threat from Russia. The Ministry of Defence does not rule out that luxury yachts, formally used for recreation, may in fact serve as platforms for intelligence operations. Such vessels, equipped with advanced technology, are capable of discreetly placing sensors or launching drones, remaining above suspicion due to their civilian status.

The situation is aggravated by the general deterioration of relations between London and Moscow. In April 2025, the UK tightened control over shipping in its waters, increasing patrols of the North Sea and the Atlantic. According to the Royal Navy, at least five cases of suspicious activity by foreign vessels near critical infrastructure facilities have been recorded over the past three months. In particular, in March, a coastguard ship intercepted a drone of unknown origin near the Orkney Islands, where key internet cables link Europe and North America. Although there is no direct evidence of Russia's involvement in this incident, the Ministry of Defence is leaning towards the version of coordinated actions.

The British authorities’ response was immediate. In early April, the government announced an additional £150 million to upgrade underwater surveillance systems. The program includes the purchase of new minesweepers and the expansion of the capabilities of vessels like the RFA Proteus to detect and neutralize threats. British Defense Secretary John Healey said the country “will not allow its maritime borders to become vulnerable” and intends to give a decisive response to any attempts to undermine security. At the same time, London called on NATO allies to step up joint patrols of the Atlantic, pointing to Russia’s growing activity in the region.

Russia has not yet officially commented on London's accusations. However, experts believe that this is yet another piece of anti-Russian propaganda.