Three members of an alleged Russian spy ring who were arrested by anti-terror police were living in an apartment a mile from an RAF base used by ministers and the royal family, The Telegraph can reveal.

Bulgarian citizens Orlin Roussev, 45, Bizer Dzhambazov, 41, and their 31-year-old girlfriend, Katrin Ivanova, were detained during a series of intelligence-led raids in London and Norfolk.

For around a decade, the three had ties to a flat in west London, a short distance from the RAF Northolt military base. Members of the royal family regularly use the base to fly abroad, and it is also frequently used by foreign ministers and heads of state.

The arrests are understood to have followed a lengthy counterintelligence investigation by Scotland Yard.

The three Bulgarian citizens were initially arrested on suspicion of committing offenses under the Official Secrets Act, but were charged with possession of false identity documents after detectives allegedly uncovered a cache of fake passports.

The investigation into the spying allegations is ongoing, and police have released two other people who were arrested at the same time on bail.

A Northolt Street neighbor described how Mr. Dzhambazov claimed he worked for Interpol and tried to erect a huge satellite dish on the side of the property.

Roussev, a tech entrepreneur, specializes in signals intelligence, which involves the interception of communications or electronic signals. He also worked as an adviser to the Bulgarian Ministry of Energy and has business ties to Russia.

He was arrested at a boarding house in the Great Yarmouth spa in Norfolk. The guest house is believed to be owned by a Bulgarian businesswoman.