‘Russian spy ring’ could be just ‘tip of the iceberg’, security sources warn

A SUSPECTED Russian spy ring unmasked by counter-terror cops may be just the “tip of the iceberg,” security sources have warned.

Thousands of low-level spies are already in Britain, former spooks told The Sun.

It comes after five Bulgarian nationals were arrested after leading “normal lives” for more than a decade.

But hostile agents known as “clean skins” are routinely sent to Britain with no obvious links to their spymasters, intelligence sources said.

Their first task is to blend in.

Some become long-term sleepers waiting for a specific mission.

Others may gather information on a pattern of life around a target — such as where secret cables come onshore.

The third group, known as facilities agents, lay groundwork for more serious spies, assassins and saboteurs.

Colonel Philip Ingram, a former Army intelligence officer, said: “I would certainly say it’s likely there are thousands of these people across the UK — these arrests are just the tip of the iceberg.”

Former counter-terror adviser Colonel Richard Kemp said similar agents helped Putin’s killers poison Alexander Litvinenko in London in 2006.

And they probably played a role in the botched Novichok nerve agent plot that killed innocent Dawn Sturgess in Salisbury in 2018.

Col Kemp said: “We can be confident that the SVR — successors to the KGB — and the other Russian intelligence agencies have hundreds of non-official cover operatives working in the UK, with their activities stepped up since the invasion of Ukraine.”

One source said Russia’s approach was to “flood the pitch with low level operatives” to get more important agents through.

They insisted the Bulgarians were “small beer” — but added the bust could lead to more important spies.

An insider said agents would have watched them for weeks, then tried to turn them into double agents.

They added: “Only if that fails, then you arrest them.”