It is starting to become clear that what investigators call one of the most notorious mail frauds in history is hardly the work of one woman.

Over the years, the scheme centered around the French psychic Maria Duval has expanded all over the world -- using mass produced letters to rake in hundreds of millions of dollars from some of the world's most vulnerable people.

New to the investigation? Read it from the beginning

Germany, Italy, Denmark, Finland, Austria, Norway, New Zealand, Australia, the United States and Canada. When one country shuts it down, it quickly pops up in another. Most recently, this scam has appeared in Japan and Russia.

As we dug through online records and government documents, our hunt for the globetrotting woman whose name is behind this multimillion dollar fraud took us on a twisted treasure hunt around the world. And instead of finding the woman herself, we stumbled upon a tangled web of shadowy characters and shell companies.

Many of these companies appear to have churned out letters from Maria Duval for decades -- soliciting payments for little more than worthless trinkets and empty promises.

Every time we thought we had found the true mastermind behind the operation, another person or business would surface -- leaving us even more confused than we had been at the beginning. Many of these leads seemed to simply be fronts or shell companies, and the names of directors just ways to disguise the true ownership.

But as we broke through the layers shrouding the Duval empire, we ended up with some new hypotheses about who has really been pulling the strings.

Before we get to that though, let's start at the beginning.

Locks of hair and truckloads of letters

We started our hunt in the United States where a lawsuit was filed in 2014 by the Department of Justice seeking to stop Duval -- along with another French clairvoyant named Patrick Guerin. (We tried to reach Guerin, but he hasn't responded to our inquiries.)

The lawsuit reads like the plot of a B movie. Duval's letters allegedly originated from a small Canadian company named Infogest Direct Marketing. (Remember this name, you'll hear it again).

In an apparent attempt to evade authorities -- who had tried to shut down the mailings before -- Infogest sent the letters zigzagging around North America before they landed in victims' mailboxes. (In a response filed in court, Infogest has acknowledged that it "arranged to send" the letters but denied any wrongdoing.)

Here's a look at their path, as detailed by the Department of Justice:

A company in Canada was hired by Infogest to print Duval's letters, which were addressed to thousands of mainly elderly Americans whose names had been bought from data brokers. The letters were then shipped by truck across the Canadian border by the same company to Albany, New York, where they were mailed out in batches of as many as 50,000 at a time.

Recipients of the letters were instructed to mail payments, personal information, photos and even locks of hair (as requested by Duval to help her hone in on each person's energy for better readings.) The responses were sent to a Hong Kong-based company called Destiny Research Center at one of its U.S. or Canadian addresses. But these addresses were just commercial mailboxes that had been opened by Destiny Research Center.

At these mailbox locations, the victims' responses were bundled and sent to a completely different company in Long Island, New York. This company, Data Marketing Group (which settled the charges and denied any wrongdoing), was allegedly in charge of processing payments and directing another company to send out the talismans, like a "Vibratory Crystal," which were actually cheap trinkets from China.

While individual payments were typically small -- around $40 or $50 each -- they added up to millions. Data Marketing Group allegedly processed as much as $500,000 every two weeks, while promptly throwing away any personal mementos like hair and photos that people had sent, according to the DOJ.

Victims were then added to a comprehensive database, and new letters asking for additional payments were triggered -- starting the cycle all over again.

Elderly, broke and homeless: The victims of a $200 million psychic scam

In late 2014, the Department of Justice shut down the sprawling business network by barring both Data Marketing Group and Infogest Direct Marketing from sending out letters in the United States -- at least temporarily. As part of this, around a dozen boxes of incoming payments were seized. A criminal investigation is ongoing, and we've tried reaching out to the companies and attorneys with no response.

But U.S. investigators haven't pinpointed who is behind the scheme's global operations -- in large part because they lack enforcement power in other countries. So we used this case as a jumping off point and started investigating the international network on our own.

Super Green Lawn Seed?!

At first, we were convinced that an Australian man by the name of Joseph Patrick Davitt and the company he is a director of, Listano Limited, were key to unlocking the mystery of Maria Duval.

Listano appears in the domain registrations of Mariaduval.com and Mariaduval.net, both of which became inactive shortly after we started our investigation. Listano is also listed as the current owner of international trademarks for Duval's name -- meaning the firm is able to use it for business purposes.

But as we looked into Davitt further, we wondered whether he might just be someone hired to conceal the real ringleaders. We came across what we think is his LinkedIn profile and saw that he currently runs his own marketing firm in Australia. His website has since gone down for maintenance, and he has apparently deleted his LinkedIn profile.

When we tried calling his marketing firm (which seems to be unrelated to Listano and Maria Duval), he answered the phone "Joe Davitt," but went silent as soon as we mentioned we were reporters looking for Maria Duval.

After hanging on the line for a minute or so, he hung up entirely. We called back multiple times only to hear a woman's recorded voicemail for his marketing firm.

Interestingly, when we called back a week later, the same woman's voice was on the voicemail, but the greeting had been changed to say we had reached SuperGreen Lawn Seed.

We did a quick search for SuperGreen Lawn Seed, and it appears to be another one of Davitt's businesses -- leaving us bewildered. We've tried calling him again since and have left multiple voicemails and sent him emails, but we have not received a response.

The address with hundreds of businesses

Not knowing where to go from this dead end, we gathered everything we could about Listano, and came across something peculiar.

While Davitt, Listano's director, is located in Australia, Listano's address was listed at 37 Greenhill Street in the quaint British town of Shakespeare's birth, Stratford-upon-Avon.

When you look up this address on Google Street View, all that shows up is a nondescript building above a fabric store and across the street from a kebab shop. There is no Listano in sight.

Confused, we searched a UK company registry database and found that more than 100 businesses have been registered to this very same address. As we scrolled through the names of the many different companies, we were shocked to see some very familiar names listed as directors.

Andrea Egger, for example, is apparently the director of an investment company listed at 37 Greenhill Street. He also happens to be a Swiss attorney who we've been told represented Duval during one of her earliest trademark applications. Meanwhile, a man named Martin Dettling is listed as a former director of a "helisports and megayacht" company located at 37 Greenhill Street. Dettling also happens to be named in the U.S. mail fraud lawsuit as the director of Destiny Research Center. We tried to reach Egger and Dettling, but they didn't respond to our messages.

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Why are so many businesses listed to this same odd address that has no business in sight? Someone must be behind it. That's when we found a curious accountant named Barney McGettigan.

His accounting firm was one of the companies listed at the address, so we decided to try giving him a call.

A cheerful British man answered the phone and confirmed that his office was the only business physically located at 37 Greenhill Street. But when we explained that we were looking for a company called Listano Limited (because of its ownership of Duval's websites), his tone quickly shifted. We couldn't record the call, but here's how we remember it from our notes.

Us: Do you work with Listano Limited?

McGettigan: Um, I'm not sure. Actually, I would have to look at our records what our association with them is.

Us: Does this mean they aren't physically located there?

McGettigan: That's correct. We offer a service to some of our clients to allow them to use our office as a registered office.

Us: We've seen a number of companies linked to the psychic Maria Duval that are registered at your address. Can we email you a list so that you can look them up in your records?

McGettigan: I'd rather not give you my email...

After this, McGettigan ended the call with an enthusiastic "Righty-ho!" and quickly hung up the phone. While he had told us he would look into Listano and get back to us, it's been months now and we have a sneaking suspicion we will not be hearing from him again. And while he may not be directly linked to Duval herself, we now know he's helping to churn out shell companies at 37 Greenhill Street, like Listano.

More hang-ups...literally

Every person we stumbled across led us to a dozen more leads. After many weeks of digging, we ended up with a long list of what we think is every single person ever associated with the Duval letters over the years.

So one day, we decided to hole up in a little conference room in CNN's New York offices and begin the confusing task of calling countries all over the world -- hoping at least one of these people could point us in the right direction.

Instead, we got hung up on a lot.

One of the first people we tried was Kaj Hvolgaard, who had been named as a Danish representative for Duval in an online news article.

An elderly sounding man with a thick accent answered the phone. When we told him we were looking for Duval, he quickly said he didn't know "the lady." But as we kept asking questions about her, he conceded that he had met her.

Who is Maria Duval? Email us with your stories, theories and feedback

"No no no no," he said, when we asked if he represented Duval. "Nothing to do with that woman. Not at all. I don't want to talk about that. It is so many years ago. I am out of that business. Thank you very much, bye."

In some cases, we didn't even have the opportunity to be hung up on. For example, we really wanted to talk to two men -- both with versions of the name Albert -- whom government business filings listed as directors of a company called Astroforce that was connected to the scheme for many years.

Bizarrely enough, British media reported that letters being sent out under variants of Maria Duval's name included photos of one of these men dressed up as a woman. But all the numbers we tried for them were disconnected. We've heard they are most likely in their 80s now, and it's unclear how involved they still are.

The only person from our marathon calling session who actually talked to us was a man named Lukas Mattle.

Remember the Canadian company named Infogest Direct Marketing that was accused by U.S. authorities of sending letters from Maria Duval? Because all of this isn't complicated enough already, there is more than one company named Infogest.

We discovered that the Canadian firm named Infogest was just a small offshoot of a Swiss company (Infogest S.A.) that was allegedly in charge of Duval's global operations, including the distribution of letters. This is where Mattle was listed as a company director, alongside his relative Beda Mattle who was listed as CEO for a number of years.

Mattle was driving through the mountains and his cell phone was going in and out of service when we called, and we had to call him back several times. He also spoke very little English. But what he did say was interesting. He told us that he had in fact worked at Infogest for a while but that the company -- and Duval -- are now "finished."

When we tried to call the company's Swiss telephone number, the line was disconnected. And a search of business records show the company was indeed liquidated in 2014. But if Infogest is out of business, how is Maria Duval still popping up in more countries, like Russia?

An inside source

After all our dead ends, we woke up one morning to a response to one of the dozens of LinkedIn messages we had blasted out to former employees of companies linked to Duval. This contact turned out to be crucial.

We spoke with him on the phone at length, but he didn't want us to name him. He said he doesn't want to be associated with what he views as an unethical company. He told us he had worked for Astroforce, one of the companies that has been most closely linked to Duval herself and listed in her website's domain history and as publisher of many of her books.

He said that we should focus our attention on two European businessmen, Jacques Michel Mailland and Jean-Claude Reuille. He said that Reuille ran both Astroforce and Infogest, though he said Reuille was careful to keep his name off of official business filings.

Mailland, he said, was the "mailing genius" who created the story behind Duval for Infogest, which then allegedly exported the letters to companies around the globe to carry out in their countries. (See Chapter 5 for Reuille's side of the story, where he emphatically denies involvement, stating he was "never an owner or manager of any Astroforce or Maria Duval companies." Mailland was unreachable.)

Our source said that because of Duval's notoriety as a psychic who could find missing people, Mailland decided to hire her to be the face and name of his new mailing campaign in the early 90s -- along with two other purported psychics.

The same anonymous employee was unsure how Duval was compensated, and he never met her in person. While he said that letters were sent from all three of the "psychics" at one point, it was Duval who became the superstar.

He said he worked there in the 90s and had heard that Astroforce shut down years ago. He was shocked to hear that the scheme was still in action.

"[There] should be some very rich people behind it," he said.

It was hard to contain our excitement while speaking with him. Not only did he give us some juicy new details, but he was adamant that Mailland and Reuille were somehow at the center of this.

These names were not new to us. Even before our interview with this employee, public documents showed a trail suggesting that these two men were once at the helm of the companies involved.

Mailland had been listed as the contact for Maria Duval's website for many years and was listed as a director of one of the Astroforce companies. Reuille has kept a lower profile, but Swiss business filings show that Infogest had a previous name -- Reuille Holding, where he was listed as director. (And there are even more connections which you'll read about next week.)

In following weeks, several other employees of Infogest also told us that Reuille had been in charge of the company, which distributed Duval letters.

But we still had questions:

Even if these men were the original masterminds (something Reuille flatly denies on his part), are they still in charge? Or have they handed off the operations to new people? Where are they now?

As we begin focusing our efforts on Reuille and Mailland, the story gets even stranger. Think UFOs, erotic massages and human cloning.

Next Thursday, we take a detour on our convoluted hunt for Maria Duval to find out more about these alleged masterminds.