Three Bulgarian citizens living in the United Kingdom who were arrested in February on suspicion of espionage offences on behalf of Russia have been charged with possessing false identity documents, police said, according to Al Jazeera.

London’s Metropolitan Police confirmed on Tuesday that Orlin Roussev, 45, Bizer Dzhambazov, 42, and Katrin Ivanova, 32, were taken into custody after they appeared late last month in the Central Criminal Court in London, according to news reports.

The trio is suspected of working for Russian security services, the BBC and other UK media have reported. The charges allege the three had false documents among 34 pieces of identification in their possession.

The BBC reported that the documents, including passports and identity cards, were from the UK, Bulgaria, France, Italy, Spain, Croatia, Slovenia, Greece and the Czech Republic.

According to the BBC, the three were detained by “counter-terrorism detectives from the Metropolitan Police, which has national policing responsibility for espionage, and are due to answer police bail in September”.

But there was no immediate confirmation by authorities of reports the arrests were made because of suspicion of links to the Russian security services.

The other two arrested, a 31-year-old man and 29-year-old woman, both from London, were released on bail and are due in court next month.

No pleas have been entered for the three people charged. Their next court date has not been set. The BBC said the three had been living in the UK for years.

The Metropolitan Police is the UK’s biggest police force and has national responsibility for matters involving espionage.

Online news site Balkan Insight said one of the suspects had a history of business dealings with Russia and previously had a role as an adviser in Bulgaria’s energy ministry in 2008-09 when it was led by a pro-Kremlin Bulgarian minister.

“Bulgaria’s energy ministry has long been seen as a lever of Russian influence,” the news site reported, adding that Russian interference in Bulgarian political life “has long been a hot topic”.

More than 100 Russian diplomats have been expelled from Bulgaria in recent years over alleged espionage and a number of Bulgarians were arrested for collaboration, Balkan Insight added.