Ask a psychic if they've ever heard of the famous French clairvoyant Maria Duval, and their responses are all over the map.

One psychic claimed she hadn't initially heard of her, but conducted a reading for us anyway (though she didn't want us to use her name):

Yes I believe she's alive.

She's using another name possibly and she may be receiving treatment for illness related to smoking. That's all I can give you. I pick up nothing about this woman, not even psychic abilities. Be careful with this person. This is not her real name.

New York medium and animal communicator Patty Payne had a different take:

Did a quick read on Maria Duval last night.

Yes she is real.

Yes she is alive.

She is retired and not doing readings professionally for the public.

A scam company co-opted her likeness and reputation and ripped people off for money. Primary focus group being seniors and those with lower educational standards. She felt the only way to "fight" this unauthorized use of her name and likeness was to retire from publicity.

And medium Katherine Horton-James from Taos, New Mexico had the most sinister prediction:

Her eyes read "Help Me..."

I feel that she went into hiding because of what she is caught in.

This is the most likely reason that you cannot find her.

I read her energy as "dead," but I believe that this is fear of what she is dealing with.

When trying to track down the elusive French psychic -- whose name is tied to one of the biggest cons in history -- it seemed only natural to start with the psychic community itself. But just like the international investigators who have attempted to shut down the scheme for decades, many of the more than a dozen psychics we talked to were unsure of her whereabouts or even her existence.

Duval has been a controversial figure for decades. To her admirers, she has been a trusted adviser and a harbinger of good luck and fortune. To her critics, she's a heartless criminal who has taken hard-earned money from elderly, lonely and depressed victims around the globe.

Read the full investigation: CNNMoney's hunt for answers about Maria Duval

Her operation has raked in all this money -- more than $200 million in the United States and Canada alone, according to the U.S. government -- through a pretty simple scheme: sending heartfelt, personalized letters selling psychic readings, lucky numbers and trinkets that she promises will change people's lives.

One victim, whose letter is included as evidence in a U.S. government lawsuit, sent Duval more than $1,000 -- hoping her psychic abilities could help them win much-needed money. After realizing it was a scam, the victim wrote to Duval one last time.

I trusted you. But you just keep wanting and wanting and sending the same letter and thinking I won't know... I don't know how you could live with your conscience.... This world is a big enough mess as it is and then people like you come along and give us hope and then we use our rent money and bill money to send to you and you get rich.

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

The U.S. Postal Inspection Service says this is one of the largest cases of mail fraud in history, misleading more than a million Americans into believing they are receiving personalized advice and unique artifacts in exchange for money. In reality, postal inspectors say the Duval letters are mass produced and the trinkets are worthless pieces of plastic from China.

While Duval's name and signature are on every letter, federal investigators haven't even been sure if Duval is the one behind this scheme -- or that she exists at all.

A simple web search reveals a number of famous Maria Duvals. The psychic we're looking for is neither the German pop singer nor the Argentine actress.

There are lots of online rumors and some tantalizing details on her Wikipedia page. For example, it says Duval's real name is Carolina Maria Gambia and she was born in Italy before moving to France. The letters state she has been practicing as a psychic for more than 40 years, making thousands of media appearances and predicting hundreds of major world events.

Some of her biggest prediction claims: the election of a black president of the United States, that the Earth will eventually explode, and that humans will one day live in space.

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Adding to the intrigue, a blonde woman with icy eyeshadow claiming to be Duval has been interviewed by journalists, appeared on TV and has spoken about her gifts on YouTube. And this same woman was featured on a website under Duval's name, which was taken down shortly after we began our investigation.

But is this woman really Maria Duval? And if so, is she really the person behind the scheme? It's clear we have a lot of work to do to find out whether there's truth to any of this.

Here's what we know so far:

It all began in 1985...

Duval's trail starts when she (or someone pretending to be her) was granted a French trademark in 1985 for the commercial use of the name "Maria Duval."

In the decades following, a number of other trademarks were issued across the globe -- many allegedly filed by Duval herself. But even attorneys who represented her told us they had never actually met or spoken to her in person.

One attorney who represented Duval in the '90s, for example, said he had dealt only with an attorney overseas, but never directly with Duval.

Later, in 2006, Duval even signed a document filed with the U.S. Patent and Trademark Office. We thought this signature could be key to finding Duval, but our repeated calls and emails to the lawyer who filed the application have gone unanswered.

Then in 2009, a Dutch firm claimed in a trademark dispute that Duval had granted it the use of her name and allowed it to "[carry] out her activities" -- hinting that others may be involved in the scheme, too.

Government investigations have gone nowhere

Despite repeated investigations and plenty of evidence that her psychic claims are pure fiction, we have not been able to find a single government agency -- in the U.S. or abroad -- that has ever been able to corner Duval for questioning. (One likely reason: Government investigators often struggle with cases like this because they lack enforcement powers outside their borders).

The Windsor Police in Ontario, for example, investigated a newspaper ad for Duval, in which she claimed "to know the secret of a mysterious 'luck attracting force' known as the Egrigor of Friday the 13th." But they told us they were never able to find the person or people responsible so no charges were ever filed.

Even the U.S. government hasn't been able to track her down. She signed a settlement with the U.S. Postal Service in 2007 in which she denied any wrongdoing, but no one associated with the case would tell us where the signature came from. And the lawyer who represented her said he couldn't talk about former clients.

And the International Consumer Protection and Enforcement Network described Duval as a "probably fictitious" character, when it led an effort to shut down her advertisements and mailings in nine countries. Actions ranged by country: Norway, for example, says that it shut down bank accounts where victims were instructed to send money and stopped newspapers and magazines from running Duval's ads.

Sightings of the psychic herself

Duval's identity has long been the subject of tabloids and other media reports.

But only a couple of journalists claim to have actually interviewed her. A woman purporting to be Duval was interviewed by an Australian radio station that made no mention of the controversy surrounding her. Instead, Duval spent the roughly 15-minute interview, which aired in early 2000, boasting about her extrasensory abilities. The interviewer even likened her to a social worker because of her claims of helping so many people. In the interview, Duval also acknowledged that a commercial had been created for her to provide help to people.

"Through my skills, our aim is to help as many people as possible," she said through a French translator. "Religion is disappearing. The family structure is no longer what it was. So most people need to refer to and to tell their troubles to somebody and I hope I am fulfilling that role."

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

Belgian journalist Jan Vanlangendonck took a more skeptical approach, documenting Duval's scam on radio and TV and eventually convincing a woman who claimed to be Duval to sit down with him at a cafe in Paris. During this TV interview, she admitted that she doesn't sign the letters herself but defended the operation -- saying that the majority of her "clients" are happy, while those who are unsatisfied are offered refunds.

We got in touch with Vanlangendonck by email and asked him what Duval was like during their 2007 meeting:

"Mad (!), but a cunning lady, sly as a fox. She never stepped out of her character," he wrote.

The trail runs cold

One of the last recorded sightings of this same woman was a high-profile appearance in Russia in 2008. It was there that she predicted that an African-American would become president of the United States (just a few weeks before the election took place).

Then in December 2008, a French newspaper heralded her return to the small town of Callas, in the wine country of southern France.

"Maria Duval: The return that nobody had predicted," the article read in French. "How long will our globetrotting psychic settle down in Callas? Nobody can predict it."

Since this return, Duval seems to have gone into retirement and/or hiding. Trademark documents show that she transferred the international rights to her name to a shell company (the same Dutch firm from the trademark dispute mentioned earlier) in late 2008, and the media appearances, YouTube videos and news articles have slowed.

But her letters have just kept coming.

It's become clear, however, that even if Duval is real and is the one who created this scheme, it is now much bigger than one woman.

From an underground operation churning out shell companies in the quaint English town of Stratford-upon-Avon to an Australian man with a lawn seed company, we've started mapping out the business web surrounding Duval. Along the way, we've come across some shadowy characters that may be behind this massive psychic scheme.

Next Thursday, we'll zero in on the international network that has allegedly kept this fraud alive around the world.