FACTBOX: What to know on expulsion of British diplomat from Russia over spying allegations

MOSCOW, March 30. /TASS/. Officers of the Russian Federal Security Service (FSB) revealed evidence of intelligence activity by a British diplomat whose accreditation has been revoked, the FSB said.

TASS has collected key insights into the situation.

- As a result of counterintelligence work, the FSB exposed undeclared British intelligence operating under the guise of the embassy in Moscow, the FSB said.

- FSB officers revealed evidence of intelligence activity by Albertus Gerhardus Janse Van Rensburg, serving as the second secretary of the British embassy.

- Also, attempts to obtain sensitive information during informal meetings with Russian economic experts were also documented.