SAN FRANCISCO (CBS SF) — Amid increasing concerns that shell companies are hiding stolen or ill-gotten funds in the United States’ luxury residential real estate market, the federal government is cracking down by requiring the buyer’s identity be revealed in all-cash luxury residential property sales, including those in the San Francisco Bay Area.

The new, albeit it temporary, regulations will cover five California counties in August, marking the second phase of a program launched by the U.S. Department of the Treasury’s Financial Crimes Enforcement Network (FinCEN).

FinCEN, starting in March, has required U.S. title insurers to reveal the identities of individuals behind legal entities that complete all-cash real estate purchases in both the Borough of Manhattan in New York City and in Miami-Dade County, Florida.

“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 when rolling out the program in Manhattan and Miami in January.

The landmark program marks the first time the federal government has required the identities of those behind all-cash real estate purchases be disclosed.

On Wednesday, FinCEN announced that their program had been so advantageous to their investigations that they are expanding it to cover six major metropolitan areas.

For six months, beginning August 28, 2016, the regulations will expand to cover any all-cash sale of $2 million or more in San Francisco, San Mateo, and Santa Clara counties, as well as Los Angeles County and San Diego County.

The program will also expand to cover all boroughs of New York City, Miami-Dade County as well as two counties immediately north, and Texas’ Bexar County, which includes San Antonio.

The expanded regulations come on the heels of a high-profile money laundering case, in which the FBI is seeking to seize over $1 billion in assets purchased with money allegedly stolen from 1Malaysia Development Berhad (1MDB), a fund owned by the Malaysian government and intended to benefit the people of Malaysia.

The FBI announced last week that, “much of the money was diverted by high-ranking fund officials and their associates to purchase yachts, hotels, a $35 million jet, artwork by Vincent Van Gogh and Claude Monet, and to bankroll the popular 2013 film The Wolf of Wall Street.” The fund officials also purchased high-end real estate in New York, Los Angeles and Beverly Hills, according to the FBI.

FBI officials said in the case of 1MDB, the diversion of billions of dollars from the fund was made possible though the use of shell companies that concealed the origin and ownership of the funds.

A statement released this week by FinCEN explains that the program was created and expanded in order to identify anonymous individuals “attempting to hide their assets and identity by purchasing residential properties through limited liability companies or other opaque structures.”

FinCEN acting director Jamal El-Hindi said the temporary program not only provides the government with a better understanding of money laundering risks in the real estate market, but will also help inform future, permanent regulations.

By Hannah Albarazi – Follow her on Twitter: @hannahalbarazi.