The defendants allegedly rented high-end apartments, paid for women’s flights and transportation, and advertised sexual services available for hourly rates that ranged from $350 to $600. Prospective buyers were instructed to fill out forms with detailed personal information, including their names, addresses, employers, and a “reference if they have one,” prosecutors said in court papers.

The Justice Department said it is investigating numerous people who may have paid for sex, including “politicians, high tech and pharmaceutical executives, doctors, military officers, government contractors that possess security clearances, professors, lawyers, scientists and accountants.” The department gave no further details about these individuals.

Tysons, where one alleged brothel was located, is a 30-minute drive from Washington, D.C. It’s a hub for Washington’s tech and defense sectors.

In an affidavit, an agent with the Department of Homeland Security said he believes there are “potentially hundreds of yet to be identified customers” who availed themselves of the scheme. The agent described using cell phone location data, physical surveillance, financial records and interviews with customers to track down information about the alleged network of brothels.

A lawyer for Junmyung Lee did not immediately respond to a request for comment. A lawyer for Han Lee declined to comment. Reached by phone, the manager for the Tysons apartment complex described in the affidavit said she had no information about the investigation.