The Justice Department charged former executives of a pharmaceutical firm with fixing generic drug prices, rigging bids, and conspiring to divvy up customers, according to court documents unsealed Wednesday.

The charges, filed against two ex-Heritage Pharmaceuticals execs earlier this week in the US District Court of Eastern Pennsylvania, mark the first time the DOJ has ever gone after a generic drug maker. It likely won’t be the last.

The charges are the first fruits of an ongoing and sweeping investigation into generic drug price-fixing by the Department. Sources familiar with the matter tell Bloomberg that the investigation now involves about two dozen drugs and more than a dozen pharmaceutical companies, including Impax, Teva, and Mylan, the infamous maker of EpiPens. The DOJ’s announcement of the charges hinted that more may be coming, including yet-to-be-named co-conspirators of the former Heritage executives.

Those defendants are Jeffrey Glazer, the former CEO of Heritage, and Jason Malek, the company’s ex-president. Both were fired in August for allegedly setting up dummy corporations that brazenly siphoned off tens of millions of dollars from the company in the course of seven years, according to a civil lawsuit (PDF) filed by the company last month.

In the two criminal cases filed this week, the DOJ alleges that Glazer (PDF) and Malek (PDF) conspired to fix the price, rig bids, and divvy up customers of the antibiotic doxycycline hyclate between 2013 and 2015. The pair also allegedly fixed the price and divvied up customers of the diabetes drug glyburide between 2014 and 2015.

In a statement, Deputy Assistant Attorney General Brent Snyder of the DOJ’s Antitrust Division said:

“By entering into unlawful agreements to fix prices and allocate customers, these two executives sought to enrich themselves at the expense of sick and vulnerable individuals who rely upon access to generic pharmaceuticals as a more affordable alternative to brand-name medicines.”

A plea hearing is set for January 9, and Glazer and Malek are expected to plead guilty.

The charges come on the heels of furor from the public and lawmakers over skyrocketing drug prices. Most notably, Martin Shkreli, former CEO of Turing Pharmaceuticals, made headlines last year for jacking up the price of a life-saving anti-parasitic medication by 5,000 percent overnight. This year, Mylan has faced harsh criticism for lawmakers for steadily raising the price of life-saving EpiPens by more than 400 percent.

While brand name drug prices have made headlines, a fraction of generics have also seen big price spikes. In an August report (PDF), the US Government Accountability Office found that about a fifth of long-standing generic drugs (more than 300 of 1,441) saw their prices jump by 100 percent or more between 2010 and 2015.

“It’s a sad state of affairs when these pharmaceutical executives are determined to further pad their profits on the backs of people whose health depends on the company’s drugs,” Special Agent in Charge Michael Harpster of the FBI’s Philadelphia Division said Wednesday. “The FBI stands ready to investigate and hold accountable those who willfully violate federal antitrust law.”