As Robert Mueller looks ever more closely at President Donald Trump's foreign business ties, one former associate has remained outside the spotlight despite playing a key role in Trump's quest for real estate deals in former Soviet lands. Architect John Fotiadis designed some of Trump's most ambitious luxury developments there. A master of glass-encased towers and monumental entrances — hallmarks of Trump's properties — the New York architect supplied vision and technical expertise that complemented Trump's salesmanship and attorney-fixer Michael Cohen's brass-tacks negotiating. Fotiadis' work offers a window into Trump's dealings in the complex, opaque world of Eurasian real estate. Today, several of these projects are reportedly under scrutiny by the special counsel, who is investigating Russian meddling in the 2016 election and any means by which Moscow might have exerted influence over Trump or his campaign, including through his business deals.

There are no indications that Fotiadis has done anything wrong and no indications that Mueller is investigating that possibility. Between 2007 and 2013, Fotiadis designed all or part of six Trump-branded developments: a Trump Tower in Kazakhstan; a Trump-branded seaside resort in the republic of Georgia; a 47-story Trump Tower in Tbilisi, Georgia; hotel rooms at the Trump Tower in Istanbul; a Trump movie studio complex in Florida; and major portions of the Trump Parc Stamford, a condominium tower in Connecticut.

Architect John Fotiadis. Source: YouTube

"The architect is a key part of the Trump sales pitch when he goes into these countries, and he's convincing the money guys to give him a branding and development deal," said Jan deRoos, a Cornell University professor of real estate finance. "The architect is the one who translates the Trump brand into actual design and construction standards." In Eurasia, Trump's deals often involved complex networks of investors and middlemen. For instance, Trump's 2011 deal to build a Fotiadis-designed resort in Georgia was set up by Giorgi Rtskhiladze, an international financier who, four years later, would arrange for Cohen to receive a proposal from a Russian millionaire seeking to partner with Trump on real estate in Russia. The McClatchy news service reported in April that Mueller's probe was looking more closely at the people involved in Trump's dealings in three countries, Georgia, Kazakhstan and Russia.

Fotiadis covers his trail

Around this time, CNBC received a tip that Fotiadis had worked on several Trump projects in Eurasia. Curious about his professional relationship with Trump, CNBC reached out to Fotiadis on April 11 for comment about this work. Fotiadis did not respond to a call or an email. But eight hours later, he announced on Twitter that he was closing his firm, John Fotiadis Architect, or JFA, after 10 years in business. A few days later, Fotiadis closed the Twitter account he had used to announce he was closing down his firm. By the end of the week, all the content from Fotiadis' professional website, including his portfolio, had been removed, leaving only a note saying he planned to join a New Jersey-based engineering company. Gone was Fotiadis' impressive portfolio of 30 projects (some of which are pictured below), including villas, schools and office buildings he has designed for clients around the world. Also gone was any reference to the two overseas branches of JFA that he had opened — in Tbilisi and Kiev, Ukraine.

The closure of JFA appears to mark an abrupt end to the solo career of an architect who counted some of the richest men in the world among his clients. Fotiadis has not answered repeated calls, emails and text messages from CNBC with questions about his work in Eurasia or why he shuttered his company. He also declined to comment on whether he had been contacted by anyone from Mueller's office. Peter Carr, a spokesman for the special counsel, also declined to comment. A half-dozen of Fotiadis' former colleagues and associates in the U.S. and Ukraine have likewise not responded to inquiries about the architect. Nor have his former clients. Fotiadis was not always so press shy. Archived versions of his website on the Internet Archive's Wayback Machine, as well as news reports and real estate industry records, reveal that until this spring, Fotidias was frequently in the spotlight. Born and raised in New Jersey, Fotiadis is in his mid-50s, with silver sideburns and fashionable, slim-cut suits. He's also highly credentialed, with a master's degree in architecture and urban design from Columbia University, licenses in New Jersey and New York, and a career spanning 30 years. Fotiadis regularly spoke at architecture conferences in the United States and Ukraine, did media interviews and traveled abroad to architectural awards shows. In one of his most recent interviews, from July, Fotiadis said he was planning to do more work in Ukraine. "We started [JFA] in 2009, and through a series of very interesting and lucky circumstances we wound up doing a lot of work in Eastern Europe, mostly in Ukraine, from 2009 to 2013," Fotiadis said in a video interview with the Kiyv Post. "Then things went dark for a while, and now I'm back, because things seem to be coming back." The interview was videoed on location at the Skyline, a high-rise condominium in downtown Kiev that Fotiadis helped design. As a speaker at conferences, Fotiadis often embraces the academic side of architecture. At the 2016 International Architecture Forum in Kiev, he delivered a keynote address titled, "Modern Architecture NOW: Form, Function, Meaning Value — A Report from New York." Fotiadis' biography posted on the IAF conference website is filled with the names of prestigious real estate developers who have hired him. It also lists cities around the world in which he has worked, including, "New York, San Francisco, Boston, Miami, Cairo, Doha, Dubai, Seoul, Moscow, Panama City, Kyiv, Donetsk, Baku, Batumi, Athens, Istanbul and Ankara."

From international jet-set clients to northern N.J.

The more one learns about Fotiadis' career, however, the more difficult it becomes to square his new job with his old one. Twelve days after announcing the JFA closure, Fotiadis became design director at SNS Architects and Engineering, a 30-person firm based in Montvale, a northern New Jersey borough. The firm's portfolio indicates that it mainly does commercial and institutional projects in the tri-state area, including car dealerships, self-storage facilities and medical labs. An SNS employee confirmed to CNBC that Fotiadis had joined the firm in April, but other SNS executives did not respond to interview requests and questions about how the firm came to hire him. His biography on the SNS website does not mention any of his former clients, although it does say that he worked on projects in Eastern Europe.

The architect is the one who translates the Trump brand into actual design and construction standards. Jan deRoos Cornell University Business School

Fotiadis' portfolio from JFA has been removed from his website, but it is still archived on the Internet Archive's Wayback Machine. There, visitors can see hundreds of images and plans from 30 projects Fotiadis has designed in the past decade for more than a dozen clients. Many of the jobs were for confidential clients. But three clients stood out. One was the Trump Organization. Another was the richest man in Ukraine, billionaire Rinat Akhmetov, who built a metals and mining empire in the chaotic decade following the collapse of the Soviet Union. Today, Akhmetov is best known to Americans as the Ukrainian oligarch who first hired former Trump campaign manager Paul Manafort in 2005 to come and work for him in Ukraine. For the next 10 years, Manafort would serve as the top consultant to Akhmetov's pro-Russia political party. Manafort is currently awaiting trial on federal money laundering and tax evasion charges stemming from his work in Ukraine. Fotiadis' third major client was the Silk Road Group, a Tbilisi-based private investment company led by CEO George Ramishvili. Silk Road Group licensed the Trump brand in 2011 for several properties in Georgia for which Fotiadis designed the plans. So far, none has been built. Neither Akhmetov nor Ramishvili started out in real estate. For them, as for many Eurasian millionaires and billionaires, property development offered a way to put to good use all the wealth and political clout they had amassed in other industries. Read more: Inside the murky world of two Eastern European oligarchs, Donald Trump and the architect they shared CNBC attempted to confirm the dates and details of the work Fotiadis lists in his portfolio for each of these clients with their representatives and lawyers. None has responded to inquiries. But there are positive testimonials on Fotiadis' website from the CEOs of Akhmetov's Esta Holdings and the Silk Road Group. Both developers emphasized Fotiadis' skill at adjusting to clients' needs and understanding their local markets. That Fotiadis' work would be in demand in Eurasia does not surprise Cornell's deRoos. "The Trump style sells well in this part of the world," deRoos said. "And the crazy thing is that these buildings are pretty transportable. So you can build the same sort of building in Baku [Azerbaijan] as in Central Park, and you develop a sort of signature." Below: The Trump Parc Stamford, one of several Trump properties Fotiadis helped design before he launched his own firm in 2009.

A view of Trump Parc Stamford tower in Stamford, Conn. Bryan Anselm | The Washington Post | Getty Images

Trump's "favorite" architect

Some of the first jobs Fotiadis did after starting his own firm in 2009 were projects for Akhmetov in Donetsk, an industrial city in eastern Ukraine. As a client, Akhmetov represented one extreme of what drives real estate development projects in Eastern Europe: the nearly unlimited resources and political clout of just one individual. A billionaire and member of parliament from the pro-Russia ruling party at the time, Akhmetov sponsored construction projects not unlike the oligarch himself: efficient, low-key and not reliant on anyone — not investors, government officials or VIPs like Trump. The Silk Road Group and Ramishvili, on the other hand, represented another extreme type of client: a developer who is overly reliant on outside forces. From the start, Fotiadis' Silk Road projects were plagued by investors who never materialized, government officials who lent support only when it served their political aims, and VIP partners like Trump, who talked a big game but ultimately contributed little. Read more: Inside the murky world of two Eastern European oligarchs, Donald Trump and the architect they shared Despite marketing himself as an Akhmetov-type alpha billionaire in total control of his projects, Trump was rarely as personally involved in his overseas licensing deals as the marketing and promotional materials made him out to be. This strategy protected Trump personally from the risk of massive losses in the event that a deal went south, such as a deal with Silk Road Group for a Trump Tower in the resort town of Batumi, Georgia. It also meant that Trump could seek out deals in less time. Below: The unfinished Trump International Hotel and Tower (left) in Baku, Azerbaijan, was another overseas project Trump launched in 2012, but was not one of Fotiadis' designs.

Artur Widak | NurPhoto | Getty Images

Fotiadis, Trump and Cohen were especially busy in 2011 and 2012. In addition to designing and pitching the Batumi project, Fotiadis designed a Trump Tower in Astana, capital of Kazakhstan, as well as a massive movie production lot for Trump in Florida. In 2011, while Fotiadis was working on the design of the Trump Batumi tower, Silk Road Group partner Rtskhiladze began talking to Cohen about trying to get funding to build another Trump-branded tower in Kazakhstan. The Trump Diamond Astana, designed by Fotiadis in late 2011, was pitched to the Kazakh government in 2012. Had it been built, the tower would have been the tallest building in Central Asia. But Trump's bid for the project lost out to a rival developer. In Homestead, Florida, Fotiadis designed what would have been the biggest studio lot in America, if it had been built. Dubbed Trump World Studios, the idea was initially brought to Trump by an ambitious elected official who was looking to score points for himself — much the way then-Georgian President Mikheil Saakashvili sought out Trump for the Batumi project in 2010. In this case, however, it wasn't a foreign president. It was Miami-Dade planning commissioner Joe Martinez, who was preparing to mount a bid for mayor of Miami. According to The Hollywood Reporter, which delved into this story in 2016, Trump hosted Martinez for dinner at Mar-a-Lago before deciding he would hire, "his favorite design firm, John Fotiadis Architect, to draw up plans." "He wanted a world-class facility," Fotiadis told THR. "It was really like a city, with residential, commercial, retail, restaurants. It even had a grid, boulevards and a main plaza." The architect added, "Trump doesn't waste people's time; when he calls, we get to work right away."

Trump doesn't waste people's time; when he calls, we get to work right away. John Fotiadis architect