Running along the north bank of the River Thames, Cheyne Walk has been home to many of London’s richest residents. James Bond author Ian Fleming once lived there; so did at least two members of the Rolling Stones.

In 2018, OCCRP’s Armenian partner, Hetq, discovered more denizens of the posh Chelsea neighborhood: the wife and sons of the president of Armenia at the time, Armen Sarkissian, were registered to live in a five-story brick mansion there. The exact ownership of the property was hidden behind an opaque offshore company registered in the British Virgin Islands.

Now, reporters have discovered the name behind that company. On paper, the owner of the mansion is Sarkissian’s sister, Karine Sargsyan. Through different offshore companies, she also owns four other high-end London properties worth tens of millions of pounds.

For years, the ownership of these five firms was hidden from public view. But in 2022, the U.K. passed a law requiring offshore firms that own property in the country to declare their beneficial owners, which enabled reporters to discover that Karine was listed as their owner. Two of Sarkissian’s sons were also listed as persons of “significant influence or control” in two of the companies.

“New transparency rules are starting to unveil how the world’s political leaders, including those from countries with serious governance issues, own vast amounts of U.K. real estate via once secretive offshore companies,” Juliet Swann, Nations and Regions Programme Manager at Transparency International U.K., told OCCRP.

Asked for comment on the properties, Sarkissian said that in the 1990s when he first entered public service, he “made the decision to entrust my wealth — earned from developing software and video games — to my sister.” This arrangement included making her the beneficiary of the companies he founded, and hiring professional managers to run them and make investments, he wrote in a response to journalists’ questions.

“Some of them [the investments] were held by companies based in the British Virgin Islands,” Sarkissian wrote. “This was a completely standard set of arrangements for managing wealth on which professional advice and expertise was received. It is largely with the proceeds of these investments that the properties you mention were bought.”

If Armen Sarkissian was the true owner of the London properties, he was required by law to declare them to the Armenian government when he returned to politics in 2013 after a stint in the private sector. But the properties don’t show up in Sarkissian’s asset declarations from 2013 to 2022.

Previous reporting has shown that Sarkissian’s declarations omitted other assets. Hetq has reported that the ex-president held an undeclared directorship of a French company that owned real estate in Paris, and that he shared a secret Swiss bank account with his sister that has held 10 million francs.

Unlike his sister, who spent years working as a doctor at Armenian state hospitals, Sarkissian is a successful businessman who would have little trouble affording luxury properties. In the early 1990s, Sarkissian cashed in on the video game boom, co-inventing the Tetris spinoff Wordtris, which appeared on Nintendo’s popular SNES and Game Boy systems.

U.K company records show that his sons became persons of “significant influence or control” in two of the BVI companies behind two of the London properties as of February 2022, less than a month after Sarkissian abruptly resigned as Armenia’s president.

“In 2022, after my retirement from politics, and as she was approaching her 70s, my sister gifted two properties to my sons, while continuing to own the remainder,” Sarkissian told OCCRP.

Sarkissian’s stated reasons for stepping down from office after four years included his belief that the Armenian presidency lacked the authority to influence important issues, as well as health problems resulting from political “attacks” against him and his family.

He left office just days after receiving questions from Hetq and OCCRP reporters for a story that revealed he held a passport from the Caribbean nation of St. Kitts and Nevis while in office.

It is a violation of the constitution for an Armenian president to hold foreign citizenship, and authorities are currently investigating whether Sarkissian committed a criminal offense, the Armenian prosecutor’s office told OCCRP.

While working in the private sector prior to his 2013 return to public service, Sarkissian also held British citizenship, U.K. corporate records show. According to a spokesperson, he gave up his British passport as required before being named his country’s ambassador to the U.K. that year.

During his time in the private sector, Sarkissian took up advisory positions at a handful of European foundations and companies, including the French telecommunications giant Alcatel Trade International AG and British Petroleum. He also founded a consulting firm called Eurasia House International.

It was also during this period — between 2000 and 2008, property records show — that four of his family’s five London properties were purchased.

Corporate records show that each of the properties is owned by a separate company registered in the British Virgin Islands. One of these firms owns the five-story brick building on Cheyne Walk, while another owns a neighboring property on the same street. A different firm owns a third-floor flat at Evelyn Mansions, just a 10-minute walk from Buckingham Palace.

Another company owns The Mulberry, a country mansion on the outskirts of London in the affluent village of Virginia Water. The house next door was owned by Gulnara Karimova, daughter of the late Uzbek dictator Islam Karimov, until it was confiscated by Britain’s Serious Fraud Office in August.

The purchase prices of two of the properties — one of the Cheyne Walk mansions and the Evelyn Mansions flat — are not publicly available, but according to online real estate databases, they are estimated to be worth a total of at least 6 million British pounds today. The other two mansions were purchased in 2006 and 2008 for a total of 24 million British pounds.

Late last year, Karine Sargsyan declared she was the owner of a fifth property, a central London flat that was acquired by another BVI firm in 2018. Its value is currently estimated at 789,000 British pounds.

Sarkissian told OCCRP that the properties “were not initially purchased at their current high values,” although he did not elaborate on how much his family had paid to buy them.

“The appreciation of their value over the years suggests smart investment rather than, as you seem to imply, extravagant expenditure,” he said, adding that the purchase of “some of the property” was financed by a loan.

Records show a mortgage taken out on 12-14 Cheyne Walk, but it was registered in 2018, a decade after the purchase.