WASHINGTON (NewsNation Now) — The U.S. Justice Department sued Walmart Inc on Tuesday, accusing the retailer of fueling the opioid crisis in the country and ignoring warning signs from its pharmacists, according to a court filing.

The lawsuit, filed in the U.S. district court in Delaware, alleges Walmart failed to take its gatekeeping duties as a pharmacy seriously.

Federal law required Walmart to spot suspicious orders for controlled substances and report those to the Drug Enforcement Administration, but prosecutors charge the company didn’t do that.

Walmart couldn’t immediately be reached for comment.

The company, which is the world’s biggest retailer, created a system that turned its 5,000 in-store pharmacies into a supplier of highly addictive painkillers, dating as early as June 2013, the lawsuit said.

Walmart’s actions helped “fuel a national crisis,” said Jeffrey Bossert Clark, the acting head of the Justice Department’s civil division, who declined to say how much precisely the government was seeking in penalties from Walmart.

The retailer’s shares fell about 2% following the news.

The government’s complaint also said “Walmart managers put enormous pressure on pharmacists to fill prescriptions – requiring pharmacists to process a high volume of prescriptions as fast as possible, while at the same time denying them the authority to categorically refuse to fill prescriptions issued by prescribers the pharmacists knew were continually issuing invalid prescriptions.”

Walmart issued a statement Tuesday reacting to the lawsuit:

The Justice Department’s investigation is tainted by historical ethics violations, and this lawsuit invents a legal theory that unlawfully forces pharmacists to come between patients and their doctors, and is riddled with factual inaccuracies and cherry-picked documents taken out of context. Blaming pharmacists for not second-guessing the very doctors the Drug Enforcement Administration (DEA) approved to prescribe opioids is a transparent attempt to shift blame from DEA’s well-documented failures in keeping bad doctors from prescribing opioids in the first place.

In contrast to DEA’s own failures, Walmart always empowered our pharmacists to refuse to fill problematic opioids prescriptions, and they refused to fill hundreds of thousands of such prescriptions. Walmart sent DEA tens of thousands of investigative leads, and we blocked thousands of questionable doctors from having their opioid prescriptions filled at our pharmacies.

By demanding pharmacists and pharmacies second-guess doctors, the Justice Department is putting pharmacists and pharmacies between a rock and a hard place with state health regulators who say they are already going too far in refusing to fill opioid prescriptions. Ultimately, patients are caught in the middle.

Walmart already sued the Department and DEA to stand up for our pharmacists, and we will keep defending our pharmacists as we fight this new lawsuit in court.

The allegations come months after the retailer filed a preemptive lawsuit in October against the federal government.

In its lawsuit, Walmart said the Justice Department’s investigation — launched in 2016 — had identified hundreds of doctors who wrote problematic prescriptions that Walmart’s pharmacists should not have filled. But the lawsuit charged that nearly 70% of the doctors still have active registrations with the DEA.

Walmart’s lawsuit alleged the government was blaming it for the lack of regulatory and enforcement policies to stem the crisis. The company is asking a federal judge to declare the government has no basis to seek civil damages; the suit remains ongoing.

The opioid epidemic has claimed the lives of roughly 450,000 people across the United States since 1999 due to overdoses from prescription painkillers and illegal drugs.

The Associated Press and Reuters contributed to this report. All reporting by David Shepardson and Mark Hosenball of Reuters and Michael Balsamo of AP.