When you think of something as mundane as laundry, you don’t think of the gold-plated Trump Organization. Yet the business of selling multimillion-dollar condominiums — a sector where the Trump name looms large — is deeply entangled with a certain kind of washing.

Money laundering.

A peculiar problem of despots and crime lords the world over is how to make dirty money look clean. Years ago, a federal prosecutor in Miami told me that cocaine cowboys would take as little as 50 cents on the dollar for seemingly legitimate income, passing their money through car washes, vending machines, convenience stores and other cash-intensive businesses. They even paid elderly pensioners steep commissions to deposit drug money in their innocent-looking bank accounts, then draw it back out as honest tender.

But few laundries can match the efficiency of an eight-figure luxury condominium in New York or San Francisco or South Florida. It works like this: The holder of a great deal of tainted money sets up a shell company, funds it through the shadow banking system, then uses the shell to purchase exclusive property. Voila! No one knows where the money came from or who the buyer might be. But when the condo is eventually resold, the proceeds emerge from the spin cycle as clean as Eliot Ness.

(Victoria Walker,Peter Stevenson/The Washington Post)

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Given the scrutiny special counsel Robert S. Mueller III is likely to bring to Trump Tower in coming months, the good news for the president is that this unsavory customer service is completely legal in most cases. Thanks to the lobbying power of the real estate industry, efforts by national and international law enforcement to crack down on corrupt money flows have scarcely touched the condo trade. Unlike bankers, who are required by law to be diligent about the sources of incoming money, condo developers and real estate agents don’t have to ask where the cabbage comes from for their all-cash sales to hidden buyers.

I asked Ross Delston, a D.C. attorney and anti-money-laundering expert, what a law-abiding developer in Manhattan, say, is legally required to do to make sure the anonymous buyer of a $50 million penthouse is not Vladimir Putin or the Sinaloa Cartel.

“Nothing,” Delston answered.

Loopholes in U.S. regulations serve to “carve out an area that money launderers use all the time: high-end real estate,” Delston said. So flagrant is the flood of soiled money in this age of kleptocracies and digital mobsters that the Treasury Department’s Financial Crimes Enforcement Network (FinCEN) has identified a half-dozen U.S. real estate markets for heightened scrutiny. New York is on the list, and South Florida, as well as the Bay Area, Los Angeles, San Diego and San Antonio. The Trump Organization is active in at least half of these markets.

Yet FinCEN continues to “tiptoe around the real estate industry,” in Delston’s words. Rather than require due diligence from sellers and agents in the targeted markets, Treasury has assigned the title insurance industry to serve as watchdogs. But in these cash transactions, parties are free to skip title insurance entirely.

An investigation by the New York Times disclosed the tip of this rotten iceberg in 2015. Reporters spent more than a year piercing some of the many shell corporations set up to obscure luxury condo purchases on Central Park South in Manhattan. Along with chief executives and celebrities buying primo properties, the Times found miscreants and crooks.

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At the Trump International, on the southwest corner of Central Park, the Times noted that more than half of all condo sales were to hidden buyers. A more recent study by USA Today found that the number of veiled transactions involving the Trump Organization took a big jump as the boss man’s political fortunes rose. Since Trump captured the Republican nomination last summer, the share of hidden buyers of his branded properties has climbed to 70 percent, the newspaper found.

The president may be waking to the possibility that Mueller will drag this unseemly marketplace into the glare of public scrutiny. In a revealing interview with the Times last month, Trump signaled that he expects investigators to find some transactions that will undercut his claims to do no business with Russia. “I mean, it’s possible there’s a condo or something,” he said. “I sell a lot of condo units, and somebody from Russia buys a condo, who knows?”

Exactly. Who knows? Our president has been operating for years in an industry notorious for blurred lines between honest and dishonest money. Whether he and his family have managed to walk this tightrope without slipping is something only time, and Mueller, will tell.

Read more from David Von Drehle’s archive.