Ukrainian forces have used British drones to attack deep inside Russia’s mainland for the first time, according to a report.

In an indication of deepening military ties between the UK and Kyiv, Ukrainian army sources told The Times that drones made by two British companies have been supplied to Ukraine and used in attacks over the past six months.

The drones have been used to attack targets deep inside Russia, including oil refineries in Volgograd and near Moscow and logistics hubs, according to the report.

Kyiv’s intensifying and deepening drone attacks inside Russia, which have also targeted transport infrastructure and sites belonging to Russia’s largest online retailer, Wildberries, have been crucial in inflicting heavy damage on Moscow’s economy.

The revelations will further deteriorate the relationship between the UK and Moscow, as tensions increase over the presence of Russian vessels near UK waters, and the chief of defence staff declaring that the UK is facing the highest level of threat from Russia since the Cold War.

“Russia has been very effective at keeping the West nervous about hitting it too hard. These attacks mean the UK is effectively signalling to Russia and our allies that we’re not [nervous] any more,” one defence source told the newspaper.

The Wiltshire-built Nyan drone, developed by BAE Systems subsidiary Callen-Lenz and tested by the Royal Navy, was used to strike Belgorod near the Russian border, the report said.

First tested by BAE Systems this summer, the drone has a wingspan of 2.9 metres and can fly more than 150 miles (241km), the defence company said on its website.

“We deliver a range of capabilities into the UK MoD as part of the UK’s support to the defence of Ukraine,” the company confirmed to The Times. “The Nyan uncrewed air system provides a rapidly developed platform proven in meeting emerging threats within highly contested environments.”

The second drone used by the Ukrainian military and made in British factories has a range of more than 600 miles (966km), and is launched using a catapult system allowing them to be fired in quick succession, the report added.

Ukraine’s long-range drone warfare has transformed the war. On Sunday, Kyiv attacked what was reportedly the country’s largest Wildberries site, situated near Moscow, in a huge overnight air attack that including more than 800 drones, according to Russian authorities.

While the UK has provided Kyiv with Storm Shadow missiles, the supply is finite and their range goes only around 155 miles (250 kilometres).

Earlier in the year, former chancellor Rachel Reeves confirmed a £752m payment to Ukraine, part of a larger £3.36bn loan, which was earmarked to procure essential military equipment, including long-range missiles, advanced air defence systems, and drones.

Last year, it emerged that British parts had also been found in Russian drones. Volodymyr Zelensky called in October for more stringent sanctions against British companies implicated in supplying components for Russian drones, which are actively being deployed in attacks across Ukraine.

He said that microcomputers for flight control, manufactured in the UK, were discovered in drones involved in a deadly assault. Other parts from allied countries, including the US, were also identified.