Two women who were part of a Russian spy network run from the UK are named for the first time today by a BBC investigation.

Bulgarian nationals Cvetelina Gencheva and Tsvetanka Doncheva took part in elaborate surveillance operations against people spied on by the cell.

Neither woman answered questions when contacted by the BBC.

Ms Gencheva, an airport worker, hung up when contacted by phone, and said she did not want to comment on the case in response to a subsequent letter.

Ms Doncheva denied being herself and walked away when approached near her home in Vienna, Austria.

Six other Bulgarians are awaiting sentencing in London for their roles in spying for Russia as part of the cell.

Police described the network as a “highly sophisticated” operation that threatened lives. Three pleaded guilty, admitting knowing they were working for Russia, while three more were convicted this month after a trial at the Old Bailey having failed to persuade the jury that they didn’t.

The cell was directed from abroad by Jan Marsalek, originally from Austria, who was a business executive in Germany who became a Russian intelligence asset. The cell’s targets included journalists who have investigated Russian espionage. One, Roman Dobrokhotov, told the BBC he believed Vladimir Putin was ultimately responsible.

The court heard about two mystery women who took part in surveillance operations in Europe.

The BBC tracked down and confirmed the identities of both women through open source digital research and speaking to sources.

Ms Gencheva, who lives in the Bulgarian capital Sofia, exploited her work in the airline industry to obtain private flight details of people targeted by the cell.

Spies followed the people onto planes and were booked in nearby seats, getting so close as to see what was being typed into their targets’ mobiles phones, even at one stage identifying a Pin number for a phone belonging to journalist Roman Dobrokhotov.

Ms Gencheva was part of a team sent to Berlin to spy on Mr Dobrokhotov, and she was a member of chat groups with three of those convicted of spying in the UK case – cell leader Orlin Roussev, Biser Dzhambazov and Katrin Ivanova – which were used to co-ordinate the spying.

She provided flight details for journalist Christo Grozev, and was tasked with gathering as much travel information as possible on another target of the cell, Russian dissident Kirill Kachur.

During the Old Bailey trial, the mystery airline worker was known as “Cvetka” or “Sveti”.

The BBC first identified Ms Gencheva through her social media profiles. On Facebook, she had interacted with Katrin Ivanova and Biser Dzhambazov.

We then found she was an airline worker.

According to her Linkedin profile, she has held positions in ticket sales for travel companies. Bulgarian company filings say she is the sole owner of International Aviation Consult.

Screen captures of travel data found on a hard drive belonging to cell leader Roussev were from airline industry software known as “Amadeus”.

On her LinkedIn profile, we found Ms Gencheva noted her proficiency with the software.

After the BBC’s research identified Ms Gencheva, a source confirmed to the BBC that she is known to the Bulgarian security services as being connected to the spy network. She is not charged with any offence.

We contacted Ms Gencheva on a Bulgarian phone number she uses for real estate work. She hung up when informed the call was from BBC News and was being recorded, not even waiting for an explanation of what we were calling about.

In response to a letter setting out the evidence relating to her, she said she did “not wish to comment on the case” and did not consent for her name to be used. Writing in Bulgarian, she claimed not to speak English well. However, her public LinkedIn profile lists her English ability as “full professional proficiency” and says she has studied in English to degree level.

Ms Doncheva helped spy on the investigative journalist Christo Grozev in Vienna, occupying a flat opposite where he lived and operating a camera that took images of his home.

She was paid to conduct an anti-Ukraine propaganda campaign, which included putting stickers on locations including Vienna’s Soviet war memorial and was intended to make supporters of Ukraine appear like neo-Nazis.

The BBC identified Ms Doncheva through her social media profiles after the Old Bailey trial heard about a “Tsveti” who had worked with the cell. Sources in Austria then confirmed her identity.

In Vienna, she met at least three of those convicted of spying in the UK case – Vanya Gaberova, Biser Dzhambazov and Katrin Ivanova.

Senior Austrian officials, including the head of the Secret Service Omar Haijawi-Pirchner, were among those selected for surveillance by Ms Doncheva, alongside the Austrian investigative journalist Anna Thalhammer, who has written about Russian espionage.

Ms Doncheva, who is unemployed, was arrested by Austrian police in December.

Court documents first reported by the Austrian magazines Profil and Falter, and later seen by the BBC, reveal she is “strongly suspected of having committed the crime of secret intelligence to the detriment of Austria”.

She told investigators she conducted surveillance after being asked by long-time friend Vanya Gaberova – one of the six Bulgarians awaiting sentencing. She said Gaberova provided her with a list of names, addresses and photographs.

She initially told police she had been misled by the others, who first told her they were conducting a “student project” and later that they were working for Interpol. But Austrian investigators are recorded as saying it is “incomprehensible” that Ms Doncheva believed such “dubious stories”.

The documents say the intelligence cell in which Ms Doncheva operated was ultimately controlled by Jan Marsalek from Moscow on behalf of the Russian intelligence services and that evidence seized by investigators shows she was contracted by Marsalek and the UK cell leader Orlin Roussev.

The documents say Marsalek directed that Anna Thalhammer be targeted. Ms Doncheva admitted to police she had photographed the journalist’s then workplace and sought to watch her from a nearby restaurant.

Ms Thalhammer, now editor of Austrian news magazine Profil, told the BBC she was first told about being spied on last year by police, and she is now aware of being watched for some time.

“She obviously sat in front of the office in a very nice fish restaurant. I really can recommend it. She complained that it’s too expensive, that she needs more money. She got that money.”

She says “that woman” also spied on a number of “high-ranked people”.

Ms Thalhammer does not know where else she was followed, but that some of her sources were identified and attempts were made to break into their homes.

She says “Vienna is the capital of spies” but no one has been sentenced in the city for espionage and the “law here is great for spies”.

“I’m frustrated and I’m also honestly a little bit scared,” she added. “I live alone with my daughter. It’s not so nice to know that the state doesn’t take care if somebody is threatening journalists, politicians or anybody else.”

A prolific social media user – even her cat has a TikTok account – Ms Doncheva posted a photo of herself on Facebook in a Vladimir Putin T-shirt in 2022 and 2023. When someone commented that in Russia a large percentage of women want to have Putin’s baby, Ms Doncheva replied saying not only in Russia, followed by a lip-licking emoji.

Ms Doncheva denied being herself when approached by the BBC in a Vienna street and refused to answer questions, but we have verified that the woman was indeed Ms Doncheva.

When approached, she was wearing clothes and carrying items seen in Ms Doncheva’s social media posts: a distinctive blue tracksuit, a pair of glasses, and a patterned mobile phone case. We also observed her entering Ms Doncheva’s registered home address less than 20 minutes after she denied being Ms Doncheva.

She has not responded to a letter offering her a chance to comment.

The two women worked alongside the six Bulgarians who were convicted of conspiring to spy for Russia.

A cache of almost 80,000 Telegram messages between Roussev and his controller Marsalek was recovered by UK police.

The messages revealed multiple operations carried out by the cell in the years before February 2023, when their activities were disrupted by police.

The UK-based spies even targeted Ukrainian soldiers thought to be training at a US military base in Germany. Roussev and Marsalek discussed kidnapping and killing journalists Christo Grozev and Roman Dobrokhotov.

Unlike the six spies convicted in the UK, Ms Doncheva and Ms Gencheva are not in custody and have not been convicted of any offence.

The Austrian public prosecutor’s request for pre-trial detention of Ms Doncheva was rejected and she was released.

Austrian court documents state there is “no risk” of Ms Doncheva absconding because she is “socially integrated” in the country and cares for her mother, and that a risk of further crime is not particularly high given the imprisonment in the UK of others involved,

Ms Thalhammer told the BBC she “can’t understand” why the person who spied on her was released.

“Maybe [they] shouldn’t believe everything a spy says.”

She said the Austrian secret service thinks there are other spy cells and that their activity has continued after the arrest of the six Bulgarians in the UK.

Ms Gencheva has remained free in Bulgaria, publicly presenting herself as an experienced airline and travel industry professional.

After being contacted by the BBC, Ms Gencheva changed her profile name on Facebook and LinkedIn. She continues to list her proficiency with the Amadeus airline software.

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