• A Russian deserter who was an officer at a top-secret nuclear weapons facility spoke with the BBC.
• He described an atmosphere of paranoia, with personnel subjected to lie-detector tests.
• The deserter said his job involved making sure his subordinates didn't bring phones onto the base.

A Russian deserter who once served as an officer at a top-secret nuclear weapons facility in Russia said everybody at the base was regularly subjected to lie-detector tests.

The deserter, identified only as Anton for his protection, disclosed little-known details about guarding Russian nuclear weapons to BBC News.

The media outlet said it verified his unit, rank, and base using official documents.

"There are constant checks and lie-detector tests for everyone," Anton said, offering rare insight into the pervasive paranoia and surveillance on a Russian nuclear base.

Anton recounted that on the day Russia invaded Ukraine, his unit was placed on combat alert and that, "in theory," his base was ready to carry out a nuclear strike.

Anton told BBC News his unit was "shut inside the base" from day one of the invasion, going on to describe life there as regimented and heavily monitored.

"It was my responsibility to ensure the soldiers under me didn't take any phones onto the nuclear base," he said, adding that no strangers were allowed on-site and that even parental visits required clearance from Russia's Federal Security Service at least three months in advance.

The Federation of American Scientists estimated that as of March, Russia's military stockpile included about 4,380 nuclear warheads, along with some 1,200 retired warheads waiting to be dismantled.

Since the 2022 invasion, Russian President Vladimir Putin has repeatedly threatened to use nuclear weapons against Ukraine and the West. Last week, Putin approved major changes to Russia's nuclear doctrine, lowering the threshold for an attack.

Anton told BBC News he carried out his duties guarding nuclear weapons at the start of the full-scale invasion, but things changed when he was asked to deliver lectures to his troops.

Using specific written guidelines, he said, he was told to characterize Ukrainian civilians as "combatants" that should be "destroyed."

"That's a red line for me — it's a war crime," Anton told BBC News. "I said I won't spread this propaganda."

In response, Anton said, senior officers ordered him to be transferred to a regular assault brigade, preparing him to be deployed to the front lines.

But before being sent to fight, Anton signed a document refusing to participate, and a criminal case was opened against him, BBC News reported.

The outlet said it reviewed documents confirming both his unit transfer and the criminal case.

Anton managed to escape Russia with the help of an organization of deserters. He told BBC News this was only possible because he was no longer stationed at the high-security nuclear base.

He said he believed security forces were still searching for him and was taking precautions to avoid appearing on any official systems.

He also said he'd had to cut off contact with all of his former colleagues. "They must take lie-detector tests," he said, "and any contact with me could lead to a criminal case."