Vladimir Putin’s FSB security service has detained a “Ukrainian spy” working at the British Embassy in Moscow. The intelligence agency alleged a bizarre plot to stage potentially deadly “acts of sabotage and terrorism” against Ambassador Nigel Casey and other members of the UK’s diplomatic mission.
Moscow would be blamed for the attacks, in a “false flag” bid to draw Britain fully into the war against Russia and to obtain more weaponry, according to the FSB. The bombshell allegations could potentially spark fears the operation is an elaborate FSB stunt aimed at engendering suspicion between Britain and Ukraine, to disrupt a key axis of Kyiv’s defence. Moscow regularly disapprovingly depicts the UK as Ukraine’s staunchest Western ally. Footage shows the alleged 45-year old “spy” – a Russian citizen evidently employed as a security officer at the British Ambassador’s official Residence – as he was violently overpowered by masked and armed plain-clothed FSB officers in Moscow, and thrown facedown on the ground. The video purports to show a confession by the alleged SBU security service in Kyiv.
FSB still of the detention of an SBU agent from the British Embassy security (Image: FSB)
The alleged agent is accused of supplying a security and military linked Ukrainian blogger Dmytro ‘Apostle’ Karpenko with secret details about diplomats and their movements.
The purported “confession” shows the unnamed detainee claiming “the Ukrainian authorities were very interested in the information for the purpose of carrying out acts of sabotage against the British Ambassador, the Embassy, and the British Residence in Moscow”.
The detainee is shown on the FSB video saying: “I was a member of the security staff at the British Embassy in Moscow.
“Specifically, I handled security duties at the British Ambassador’s Residence in Moscow.”
This is one of Moscow’s most prominent diplomatic buildings directly across Moscow River from the Kremlin.
Detention of an alleged Ukrainian SBU agent who worked in security at the British Embassy in Moscow (Image: FSB)
“In January of this year, I contacted Dmitry Karpenko, a Ukrainian blogger and journalist – specifically, a pro-Ukrainian blogger,” said the ‘suspect’. “I told him I worked at the British Embassy in Moscow.
“He was very interested in this information – specifically, details about the Ambassador [Nigel Casey], his deputies, other diplomats, and the staff of both the Embassy and the Residence. He wanted their personal details, addresses, and full names.
“Information on the vehicles they drove, their movements, the restaurants they visited, and the cities they traveled to; and the arrival and departure times of all staff and diplomats.
“He was also extremely interested in the security arrangements – how security and protection were handled at the British Embassy and Residence in Moscow.
“This included the access control system, events held on the Residence grounds, and the number of security personnel on duty.
“In short, he wanted all information regarding the security of the British Residence and Embassy in Moscow.
British Ambassador Nigel Casey (r) pictured in Moscow in April 2025 (Image: Anadolu via Getty Images)
“When I asked why he needed this, he replied that the Ukrainian authorities were very interested in the information for the purpose of carrying out acts of sabotage against the British Ambassador, the Embassy, and the British Residence in Moscow.”
The FSB was once headed by Putin and is long suspected of staging stunts.
So far it has offered no direct proof of potentially deadly attacks targeting Britain’s ambassador and other diplomats.
WhatsApp messages were published showing the security operative’s alleged communications with blogger Karpenko. They related to movements of diplomats and who lived in the Residence and its compound.
One said: “The Ambassador’s wife lives in Britain but periodically stays here.”
Another said: “The Ambassador is due to arrive tomorrow, Sunday, at 23:25….The Deputy Ambassador went out for dinner. I don’t know with whom. She was away from 20:13 until 00:30.”
The British Ambassador’s Residence in Moscow, where the detained man allegedly worked in security (Image: Getty)
The suspect has been charged with high treason under Article 275, which can carry life imprisonment.
He was employed by an outside organisation providing security to the embassy – not directly by the British government.
Russian state news agency TASS claimed: “The Kyiv regime, in order to preserve itself, is ready to resort to sabotage and terrorist acts against its strategic allies.”
The FSB urged Russian citizens to refrain from any contact with pro-Ukrainian bloggers.
When he arrived in Moscow in 2023, Casey, 57, made a video appeal from his Residence, with the Kremlin visible, calling for the “ending the human suffering caused by Russia’s invasion of Ukraine.”