Ever fantasize about fleeing the winter cold and getting in on the ground floor of a beachfront real estate deal in which you double your money in a few years? If you’ve dreamed that dream, here’s how it could turn nightmarish.

When Frank Balluff and his wife, Rebecca, purchased a lot in what seemed to be an exciting new Caribbean resort development, little could they imagine what they were getting into. In fact, it was what the Federal Trade Commission now calls the biggest real estate scam involving overseas property it has ever investigated. Promoters allegedly fleeced 1,000-plus lot buyers out of $100 million or more. Earlier this month, the FTC sought and obtained a federal court order temporarily shutting the project down and freezing promoters’ assets.

Balluff, a business owner from Michigan, estimates that his personal losses exceed $310,000, but he says he’s heard of others who “invested their full retirement funds” and planned to build homes and move to the resort. Now “they just have nothing left,” he says.

Balluff and others — mainly Americans nearing retirement age or already retired — bought into a slickly marketed development known variously as Sanctuary Belize, Sanctuary Bay and The Reserve. The 14,000-acre project is located on the Caribbean coast in Belize, an English-speaking nation bordering Mexico.

Through advertising pitches on Bloomberg News, Fox News and infomercials, developers promised purchasers a seductive list of amenities — fine restaurants, a luxury hotel, a world-class marina and shops, a hospital staffed by Americans, a championship golf course, a casino and even an airstrip, according to the FTC. Plus they dangled financial catnip: fat and fast profits if buyers chose to sell their parcels. The promoters pushed on-site tours to people like the Balluffs, who flew to Belize to inspect the property before putting down any money. However, according to the FTC, “many consumers” purchased lots costing $150,000 to $500,000 sight-unseen.

Balluff says he was attracted by the promoters’ innovative “no-debt” approach; unlike most real estate developers, they wouldn’t depend on lenders to finance their activities. Instead they’d plow sales revenues back into the resort to speed its completion within two to five years.

High on the Balluffs’ priority list was that the project be completed as quickly as promised, because they wanted to build a home and get away from Michigan’s harsh winter weather. When they periodically inquired about progress at the site, they were assured by officials that Sanctuary Belize “would meet its timelines.” But six years have passed, and most of what was promised hasn’t been delivered. Hardly any homes have been built, according to the FTC, and Balluff says the developers seem “to be doing little more than moving dirt around and making excuses for delays.” When buyers ask for the developers to buy back their lots or they stop making payments, the developers refuse refunds and resell the lots to new buyers, the FTC alleges.

But it gets worse. To gather information on Sanctuary Belize, the FTC created a sting operation that involved a fictitious small business whose owners fit the profile of Sanctuary’s target marketing. They posed as purchasers and in the process documented disturbing facts, according to the FTC: The person orchestrating the Sanctuary development, Andris Pukke, is a convicted felon who had been sued by the FTC for consumer fraud in connection with a debt-counseling scheme; Pukke ultimately agreed to forfeit millions of dollars in assets that could be used to refund money to victims. James Kohm, director of the FTC’s consumer protection enforcement division, called Pukke “a hardcore recidivist scammer” who perpetrated the Sanctuary Belize scheme “even while serving a prison sentence for obstruction of justice.”

Sanctuary Belize officials covered up his involvement, according to the FTC, repeatedly lying to buyers such as the Balluffs, who had discovered his connection to the development after their purchase. Neither Pukke nor officials of his company, based in Irvine, Calif., could be reached for comment last week; the main number for Sanctuary Belize marketing and sales was no longer in service.

Some takeaways? First, the FTC’s allegations and injunction will need to pass further tests in court. Even if successful in permanently shutting down the Sanctuary Belize enterprise, the agency may not recover the funds needed to repay alleged victims. Second, buying into resort land developments — whether in Florida at various times in the past century or in exotic locations like Belize — has always been inherently high risk. You can never do too much due diligence, especially when checking out the promoters.