The brothers were arrested Wednesday in Florida and are expected to be extradited to New York to face sex-trafficking charges. Tal appeared in federal court in Miami on Wednesday; his brothers were in state custody. Tal walked into the courtroom with his hands and feet in shackles, wearing a gray sweater and sneakers.

U.S. Attorney Damian Williams said prosecutors interviewed dozens of women who said they were assaulted by one or more of the brothers.

“This conduct, as alleged, was heinous,” said Williams, the chief federal law-enforcement officer for the Southern District of New York. “We are committed to prosecuting sex trafficking no matter how powerful or wealthy or famous you may be.”

At a press conference in New York, Williams said the brothers weren’t acting alone but declined to comment on whether anyone else was under investigation. He reiterated the call for more victims to come forward.

Standing outside the courtroom in Miami, Joel Denaro, an attorney temporarily representing the three brothers, said his clients were facing three sex-trafficking-related charges. Soon after, a magistrate judge read out three counts against Tal. The other two brothers will likely appear in state court on Thursday, Denaro said.

The Wall Street Journal reported in July that the Federal Bureau of Investigation was investigating the brothers after three women filed lawsuits against them and several others told the Journal they were sexually assault or raped by the brothers.

Prosecutors claim the men from around 2010 until 2021 used their prominent positions in real estate to meet women whom they later sexually assaulted, according to the indictment. The men—to impair the women—would sometimes secretly spike their drinks and give them cocaine, mushrooms and GHB, according to the indictment. GHB is a depressant drug that is popular in clubs and that is also known as a date-rape drug because it can cause someone to black out.

Alon Alexander, shown in 2015. Photo: Paul Porter/BFA/Shutterstock

Tal and Oren were star brokers at Douglas Elliman before starting their own company in 2022. Allegations by women against the three men sent shock waves through the luxury real-estate world. A spokesman for Douglas Elliman declined to comment.

The arrests follow lawsuits filed by two women in March that accused Oren and his twin brother, Alon, 37 years old, of rape. A subsequent lawsuit—and accounts by women shared with the Journal—contained similar allegations against Tal Alexander, 38.

The men have denied the allegations, and their lawyers have said the civil suits were without merit.

The FBI had reached out to some women and their lawyers in recent weeks to see if the women would testify, some of the women said. But the brothers seemed to go about their lives. All three attended a Miami Dolphins game with their father, a prominent Miami businessman. Alon was spotted golfing in Miami in recent weeks.

The assertions had swirled around the three brothers for roughly two decades, a Journal investigation showed, starting when they were high-school students in Miami and later in New York as Oren’s and Tal’s careers took off at Douglas Elliman, the large brokerage known for its association with hit reality shows like “Million Dollar Listing.”

There has been a mass exodus of executives and agents from Official, the real-estate company they co-founded, in the wake of the allegations. Alon has been an executive at the family’s private security firm Kent Security but his name is no longer listed on the company’s website.

“We are glad to hear that there will finally be some measure of accountability for the Alexander brothers and justice for their many victims,” said David E. Gottlieb, a lawyer who represents some of the women who alleged sexual assault. “We applaud all the survivors who have had the strength and courage to speak up.”

—Deborah Acosta contributed to this article.

Write to Katherine Clarke at Katherine.Clarke@wsj.com and Emily Glazer at Emily.Glazer@wsj.com

Corrections & Amplifications
Isabelle Kirshner is a lawyer for Oren and Alon Alexander. An earlier version of this article incorrectly said she is a lawyer for Oren and Tal Alexander. (Corrected on Dec. 11)