Federal prosecutors on Monday indicted executives for Backpage.com on a series of money laundering and prostitution charges.

The 93-count indictment was unsealed days after authorities seized the classified ads site and reportedly raided the Arizona home of Michael Lacey, one of Backpage's founders who was named among the seven defendants.

"For far too long, Backpage.com existed as the dominant marketplace for illicit commercial sex, a place where sex traffickers frequently advertised children and adults alike," Attorney General Jeff Sessions said in a statement. "But this illegality stops right now. Last Friday, the Department of Justice seized Backpage, and it can no longer be used by criminals to promote and facilitate human trafficking."

Prosecutors are accusing Backpage of allowing prostitution ads featuring underage sex-trafficking victims.

The charges come more than a year after a Senate investigations panel accused Backpage executives of knowingly facilitating sex trafficking on its site.

That investigation also spawned a controversial bill aimed at cracking down on online sex trafficking, which critics believe could hurt internet platforms' ability to promote free expression online. The bill, called the Allow States and Victims to Fight Online Sex Trafficking Act, passed the House and Senate overwhelmingly this year and is awaiting the president's signature.

"Our bipartisan investigation into Backpage uncovered new evidence that was handed over to the Department of Justice more than 10 months ago," Sen. Rob Portman (R-Ohio), who has led the legislative effort, said in a statement. "Our bipartisan work has made a significant difference in raising awareness of these trafficking crimes and informed our efforts to craft a narrow legislative solution that is now ready to be signed into law."