The BBC revealed the arrest of three individuals suspected of being spies for Russia in Britain, and charges have been brought against them in a large national security investigation.

The accused, all Bulgarian citizens, were detained in February and have remained in custody since then.

They are alleged to have been working for Russian security services.

They have been charged with possession of "improper identity documents," and it is claimed that they knew these documents were fake.

The documents include passports, ID cards, and other documents for Britain, Bulgaria, France, Italy, Spain, Croatia, Slovenia, Greece, and the Czech Republic.

The three were arrested under the Official Secrets Act by counter-terrorism investigators from the Metropolitan Police, which is responsible for counter-espionage.

Who are these accused individuals?

Orlin Rusev, 45, Great Yarmouth, Norfolk, UK
Bayzar Dzhambazov, 41, Harrow, northwest London, Katerina Ivanova, 31

The trio had lived in Britain for years, working in a variety of jobs, and resided in a series of suburban properties.

Rusev has a history of business dealings in Russia.

He moved to Britain in 2009 and spent three years working in a technical position in financial services.

His profile on LinkedIn states that he later owned a company in the signaling field, which included intercepting communications or electronic signals.

Rusev, whose most recent address was a guesthouse by the sea in Great Yarmouth, also mentioned that he once worked as a consultant for the Bulgarian Ministry of Energy.

In Harrow, former neighbors described Dzhambazov and Ivanova as a couple.

Dzhambazov is described as a hospital driver, and Ivanova describes herself in her LinkedIn profile as a lab assistant for a private health company.

The couple, who moved to Britain about a decade ago, ran an organization providing services to the Bulgarian community, including introducing them to "British culture and standards."

They also worked on electoral commissions in London that facilitated voting in Bulgarian elections for citizens living abroad, according to Bulgarian state documents online.

Neighbors in the two homes previously occupied by the couple said they brought pastries and cakes as gifts.

They also stated that investigators spent a long time searching for them at their most recent home in Harrow, with a visible police presence for over a week.

The three accused are scheduled to stand trial at the Old Bailey in London next January. They have not yet filed pleas to the charges against them.

The Counter-Terrorism Police have publicly discussed the increasing amount of time they spend suspecting state threats and counter-espionage, particularly regarding Russia.

Their concern follows incidents in recent years related to Russian intelligence operations in Britain.

In 2018, Russian agents attempted to kill former double agent Sergei Skripal and his daughter Yulia in Salisbury, Wiltshire, using the deadly nerve agent Novichok. They were treated, along with investigator Nick Bailey, in a hospital, and could have died.

Later that year, a woman named Dawn Sturgess, who had no connection to the Skripal family, died after being exposed to the nerve agent, which had been left in Wiltshire in a perfume bottle.

Skripal is a former colonel in Russian military intelligence who was recruited by British intelligence "MI6" and was sentenced to 13 years in prison in his country after being exposed and arrested in 2006, before being exchanged along with three other Western spies by Russia for ten Russian spies arrested in the United States.

In 2006, former Russian intelligence officer Alexander Litvinenko was killed in London after being poisoned by assassins working for the Russian state.