Three suspected spies for Russia in the UK have been arrested and charged in a major national security investigation, the BBC has revealed. The defendants, all Bulgarian nationals, were held in February and have been remanded in custody since. They are: Orlin Roussev, 45, of Great Yarmouth, Norfolk; Bizer Dzhambazov, 41, of Harrow, north-west London; Katrin Ivanova, 31, of the same Harrow address.

It is alleged they were working for the Russian security services. They are charged with possessing identity documents with "improper intention", and are alleged to have had these knowing they were fake. The documents include passports, identity cards and other documents for the UK, Bulgaria, France, Italy, Spain, Croatia, Slovenia, Greece, and the Czech Republic. The three defendants were arrested under the Official Secrets Act by counter-terrorism detectives from the Metropolitan Police, which has national policing responsibility for espionage.

Mr Roussev has a history of business dealings in Russia. He moved to the UK in 2009 and spent three years working in a technical role in financial services. His online LinkedIn profile states he later owned a business involved in signals intelligence, which involves the interception of communications or electronic signals. He also states he once acted as an adviser to the Bulgarian ministry of energy.

Mr Dzhambazov is described as a driver for hospitals, and Ms Ivanova describes herself on her online LinkedIn profile as a laboratory assistant for a private health business. The pair, who moved to the UK around a decade ago, ran a community organisation providing services to Bulgarian people, including familiarising them with the "culture and norms of British society".

The three defendants are due to go on trial at the Old Bailey in London in January, the BBC writes.

Bulgaria’s ambassador to the UK and Northern Ireland Marin Raykov said, for the Bulgarian news agency BTA, that the Bulgarian embassy has not been informed, by the British authorities, of the arrest of the three individuals cited by the BBC.