According to Britain's largest intelligence agency, almost 500,000 Russian soldiers have been killed since Russia began its full-scale invasion of Ukraine in 2022.
The data was released by the director of the British cyber intelligence service, Anne Keest-Butler, in her public speech, in which she outlined the threats facing Britain and the measures she believes must be taken to counter them.
The intelligence chief warned that the United Kingdom is at a "very important moment, with Russia relentlessly attacking critical infrastructure across the country". She also accused the Kremlin of a series of espionage plots on British soil and the recent undeclared "hybrid war" against the country and other NATO countries.
While Kiev and Moscow regularly publish estimates of each other's losses, they are reluctant to give details of their own. In February, however, President Volodymyr Zelensky said that Ukraine had lost 55,000 soldiers over the past four years.
Last night, Anne Keest-Butler said in her first speech in office that Russian forces were "retreating on the battlefield" in Ukraine for the first time since late 2022. She then offered a new estimate of the number of Russian casualties, which is higher than the recent estimate of 352,000 killed by the independent Russian exile media outlet "Medusa" and "Mediazone".
Keast-Butler said there was "new intelligence indicating that almost half a million Russian soldiers have been killed since the beginning of the conflict".