Bulgarian national Tihomir Ivanov Ivanchev, 38, will appear in court on Wednesday.
A sixth person has been charged with being part of a suspected Russian spy ring operating in the UK.
Tihomir Ivanov Ivanchev, a 38-year-old Bulgarian national, from Acton, west London, was arrested earlier this month and will appear in court on Wednesday.
He is accused of “conspiring to collect information intended to be directly or indirectly useful to an enemy”.
Five other Bulgarian nationals are due to go on trial in October after being charged with the same offence.
Orlin Roussev, 46, from Great Yarmouth, Norfolk, Bizer Dzhambazov 43, and Katrin Ivanova, 32, of Harrow, north-west London, Ivan Stoyanov, 32, of Greenford, west London, and Vanya Gaberova, 29, of Euston, London, were arrested in February 2023.
It is alleged surveillance was carried out on people and places targeted by Russia between August 2020 and February 2023.
The charge faced by Mr Ivanchev alleges he acted with the five other defendants, a person named as Jan Marsalek and others unknown.
It says they”conspired… to obtain, collect, record, publish or communicate documents or information which was calculated to be, or might be intended to be directly or indirectly useful to an enemy for a purpose prejudicial to the safety and interest of the state”.
Commander Dominic Murphy, from the Metropolitan Police’s Counter Terrorism Command, said Mr Ivanchev was “was identified and arrested as a result of inquiries made following the previous five arrests in this investigation”.
Police said he was bailed after his initial arrest on 7 February and charged on Tuesday.
The Crown Prosecution Service said it had authorised the charge “against a sixth person suspected of spying for Russia”.
Mr Ivanchev is due to appear before Westminster Magistrates’ Court on Wednesday.
The other five accused were remanded in custody after appearing at Westminster Magistrates’ Court in September, and a trial date has been set at the Old Bailey.
Seaside guest house
Mr Ivanchev is listed as the owner of a London decorating business.
He is registered as having lived at the same addresses as Ms Gaberova, an award-winning beautician, who specialised in eyelashes and ran a salon called Pretty Woman in west London.
Mr Stoyanov, nicknamed “the Destroyer”, was an amateur mixed-martial-arts fighter appearing in contests in the UK. In Bulgaria he appeared in so-called combat sambo fights, a form of martial arts popular in eastern Europe.
Mr Roussev previously worked in financial services. Biser Dhzambazov and Katrin Ivanova lived as a couple and ran a community organisation for Bulgarian citizens living in the UK.
It is alleged that the operating hub in this country for the offence of espionage was a now-closed guesthouse in the seaside resort of Great Yarmouth occupied by Mr Roussev.
Mr Roussev is alleged to have organised and managed the cell’s spying operations from the UK. It is alleged that such operations took place in the UK and Europe.
The person named Jan Marsalek in the charge has not been accused in the case. Mr Marsalek is best known as the Austrian former chief operating officer of the company Wirecard, who became a wanted man in Germany after being suspected of having committed fraud. He is believed to have left Germany in 2020 and is reportedly now in Russia.
It is claimed Mr Roussev received tasking from abroad by Mr Marsalek.