Last year the Czech authorities broke up a Russian spy network operating in the country, the head of the BIS counter-intelligence service, Michal Koudelka, told MPs earlier this week.

The FSB spy ring – financed directly by Moscow and the Russian Embassy – was uncovered by the BIS counterintelligence agency and the Czech Republic's national organized crime unit, Radio Prague reported.

"Russia is not a military threat to this country [the Czech Republic] or Europe, but it is a security threat to our country and to Europe," said former Czech Military Intelligence chief Andor Šándor.

Видео дня

"If we accept the fact that for the Russians NATO is the biggest threat, we shouldn't be surprised by Russia's activities in various NATO countries – and in particular those that are not considered to be strong allies, because of the public support [for NATO] and things like that," he went on to say.

Read alsoRussia sending threatening texts to British troops – media

He added that he had long been stressing that "Russian spying activities are really big and that they are trying to make NATO less cohesive, less effective."

The information available about the extensive probe hints that the Russians' efforts included cyberattacks, aimed at various installations and institutions in the Czech Republic and across Europe.

"It's supported by Moscow, it's supported by the Russian Embassy in Prague, but the main culprit, if I can put it like this, is the FSB, as the chief of BIS said in Parliament," the expert said.

Commenting on Russia's aggressive stance toward Europe and NATO, the expert said that they "try to really influence the politicians, the decision-making process, and they try to influence public opinion and therefore political decisions."