The five Bulgarian nationals were charged with collaborating to obtain information between August 2020 and February 2023 that would be valuable to an adversary.
They allegedly performed surveillance on targets in the UK and the rest of Europe for Russian security agencies.
Police discovered forged passports and other false identification documents while searching the suspects' homes in London and Norfolk.
Other fake IDs included those for the Czech Republic, Croatia, Slovenia, Greece, France, Italy, and Spain.
Investigators assumed that Roussev was the suspected mastermind of the spy ring who created the fakes.
The Metropolitan Police's Counter Terrorism Command in London discovered the spy ring.
Prior to this, police in the UK accused three alleged Russian military intelligence agents of trying to kill a double agent and his daughter using the nerve toxin Novichok.
Evan Gershkovich of The Wall Street Journal was still in custody in Russia due to espionage allegations. (NAN)