A senior soldier in the US Army has been arrested in the UK on suspicion of spying for Russia, counter-terrorism police revealed. The 41-year-old is accused of helping a Russian intelligence service and obtaining or disclosing protected information, detectives said.

FBI Director Kash Patel admitted the case involves “allegations of espionage”. The suspect, who is in custody, was arrested near Gloucester. American military chiefs say he was “entrusted with sensitive information” in his role.

FBI Director Kash Patel said: โ€œThis important arrest involves allegations of espionage, which is of the utmost concern to the United States and our allies. While this investigation is continuing, I want to send a clear message โ€“ this FBI has no tolerance for anyone who breaks their oath to the United States and whose actions endanger our national security and that of our partners.

“This includes 167 counterintelligence and espionage arrests from this FBI over the last 21 months โ€“ a 53% increase.โ€

โ€œThis matter shows that partnerships are essential to protect our countries and I want to express my thanks to UK Counter Terrorism Policing, MI5, UK Defence Counter Intelligence, and the U.S. Army Counterintelligence Command for their outstanding work.โ€

Brig. Gen. Sean Stinchon, the commanding general of U.S. Army Counterintelligence Command, said: โ€œThis case demonstrates the strength of our partnerships and the resolve of the counterintelligence community. I am grateful to the UK and the FBI for their professionalism and teamwork throughout this investigation.

“The alleged conduct of a senior solider, entrusted with sensitive information, is a sobering reminder that insider threats are real and persistent. I encourage anyone who thinks theyโ€™ve witnessed something suspicious to report it to their local counterintelligence office.”

Intelligence chiefs believe Moscow is ramping up hybrid warfare attacks in Europe, motivated by hostility towards the West’s support for Ukraine.

Deputy Assistant Commissioner Vicki Evans, Senior National Coordinator for Counter Terrorism Policing, said: โ€œThis significant arrest and investigation is a result of close collaboration between UK and US authorities.

“The allegations are serious and our investigation is very much ongoing. This activity demonstrates the strength of our UK and US law enforcement and national security partnerships, and I commend the work of all the teams involved. We will work together to take robust action against those we suspect of any criminal activity that could undermine our national security.”

Sir Ken McCallum, the head of MI5, warned in his annual threat update that Russia remains “aggressor number one”.

And intelligence chiefs fear they will continue attempting to wreak havoc for years.

He said: โ€œWe are planning on the basis that these risks will endure. Some of these vulnerabilities are inherent in handling an open society in a connected era, AI isnโ€™t going away, there isnโ€™t a probability that that will be something that is going to go away by the end of next year.

โ€œIrrespective of what happens in Ukraine, it is quite hard to see the Kremlin suddenly decide to rub along with us all after all.

โ€œSo we are planning that this is going to be a long-haul contest.”