UPDATED 01/13/2016 5:49 p.m.: In a move that could send shock waves through Miami and Manhattan’s luxury real estate market, federal authorities announced Wednesday that they will soon require title insurance companies to reveal the true names of high-end homebuyers.

Starting March 1, title insurance companies will be required to disclose the true owners of shell companies that drop $1 million and over in cash for Miami properties. The order, which expires August 27, was issued by the Financial Crimes Enforcement Network in a bid to help curtail money laundering in high-end real estate.

South Florida is well known for its attractiveness to wealthy buyers, who regularly pay top dollar for luxury houses in ritzy neighborhoods like South Beach and Indian Creek. Also commonplace is the use of shell companies that keep the true players behind the scenes — a practice that some money laundering experts expressed worry over, especially during South Florida’s housing crash.

“There is a wave of willful blindness about the source of a good portion of the money coming into real estate investments in South Florida,” former assistant U.S. Attorney Charles Intriago told The Real Deal in 2013. “There is no way in hell that all of that money is coming out of Mother Teresa’s convent.”

FinCen officials said in the Wednesday announcement that the agency had already put protections on real estate deals that include mortgages, so it’s shifting its attention to all-cash transactions. Miami sees more cash sales than almost anywhere else in the nation. In September, for instance, more than half of all Miami-Dade County’s home purchases were done without financing.

“We are seeking to understand the risk that corrupt foreign officials, or transnational criminals, may be using premium U.S. real estate to secretly invest millions in dirty money,” FinCEN Director Jennifer Shasky Calvery said in a statement. “Over the years, our rules have evolved to make the standard mortgage market more transparent and less hospitable to fraud and money laundering.”

Miami is no stranger to secret buyers: Last week, a mysterious party paid $47 million for the former Matheson estate in Key Biscayne using a Delaware limited liability company. Even the buyer of Faena House’s $60 million penthouse, Ken Griffin, remained in the shadows through a shell company until someone involved in the deal broke the silence.

However, recent months have seen Miami’s luxe residential market start to tighten, thanks in large part to falling currency values abroad discouraging foreign buyers. With this new lack of privacy, real estate attorney Joe Hernandez said foreigners will just have another obstacle to cross before trading real estate here.

Hernandez, who works for law firm Weiss Serota Helfman Cole & Bierman, said a wealthy buyer’s reasons for keeping private are two-fold: minimizing their presence in the U.S. for tax purposes, and keeping themselves from entering the public spotlight.

“I have wealthy clients from New York — hedge funders, private equity guys — they don’t want the world to know they have a condo down here,” Hernandez said.

But at the end of the day, Hernandez said the rules won’t deter someone who isn’t breaking the rules.

And while this move by FinCen is only temporary, it sends a clear message: “They did it once; they can do it again,” Hernandez said. — Sean Stewart-Muniz