Walmart has been sued by the Justice Department, which alleges that the company’s pharmacies illegally distributed controlled substances helped sustain the U.S.’s opioid crisis.

The civil complaint filed on Tuesday indicates that it’s possible that Walmart’s pharmacies aided the crisis by "filling opioid prescriptions and by unlawfully distributing controlled substances to the pharmacies during the height of the opioid crisis," the Associated Press writes.

Federal authorities also allege “hundreds of thousands of violations” of the Controlled Substances Act, and are pursuing penalties that number in the billions, per USA Today. Walmart has over 5,000 in-store pharmacies across America.

“As one of the largest pharmacy chains and wholesale drug distributors in the country, Walmart had the responsibility and the means to help prevent the diversion of prescription opioids,” said Jeffrey Bossert Clark, the acting chief of Justice's Civil Division. “Instead, for years, it did the opposite ... This unlawful conduct contributed to the epidemic of opioid abuse throughout the United States.”

Timothy Shea, acting head of the Drug Enforcement Administration, added that the company’s pharmacies commonly filled “illegitimate” prescriptions. “Too many lives have been lost because of oversight failures and those entrusted with responsibility turning a blind eye," he added.

The Justice Department hasn’t formally announced the charges, but the news comes after a years-long investigation by its Prescription Interdiction & Litigation Task Force. It also arrives almost two months after Walmart filed its preventative lawsuit against the DOJ, Attorney General William Barr, and the Drug Enforcement Administration.

Walmart’s lawsuit alleged that the DOJ’s investigation—which was initially launched in 2016—had pinpointed hundreds of doctors who wrote questionable prescriptions that Walmart pharmacists shouldn’t have fulfilled. And according to the suit, the company claimed that almost 70 percent of those doctors still have active registrations with the DEA.

The lawsuit also alleged that the government was falsely accusing the company for its inadequate regulatory and enforcement policies to contain the opioid crisis. Walmart is requesting a federal judge dismiss the government’s civil complaint, though no decision has been made.