The suit was announced Tuesday.

The Justice Department on Tuesday announced it is suing Walmart, accusing the company of helping to fuel the U.S. opioid crisis by unlawfully distributing controlled substances at its pharmacies around the country.

The department’s lawsuit alleges that for years, Walmart’s pharmacies unlawfully filled thousands of prescriptions for opioids without required care and investigation, including prescriptions pharmacists knew were suspect.

The lawsuit also accuses Walmart of failing to detect as many as hundreds of thousands of suspicious orders of opioids and report them to the Drug Enforcement Administration, even as the company allegedly knew that its internal monitoring systems were “grossly inadequate” for years.

In a statement responding to the lawsuit, Walmart accused the Justice Department’s investigation of being ” tainted by historical ethics violations” and that the lawsuit “invents a legal theory that unlawfully forces pharmacists to come between patients and their doctors.”

The lawsuit, Walmart alleges, 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,” according to its statement.

“Walmart had important gatekeeping responsibilities to ensure that prescription opioids and other controlled substances were used legitimately and not abused,” said DOJ’s acting Civil Division chief Jeffrey Bossert Clark in a briefing with reporters Tuesday. “But in both roles Walmart violated the law and Walmart’s unlawful conduct, which occurred nationwide, had disastrous consequences and harmed the many individuals who filled their prescriptions at Walmart and then abused the drug and it helped fuel a national crisis.”

One allegation outlined in the complaint says that in Florida, “pill mill” doctors, who often give improper prescriptions to thousands of individuals, would tell their customers to bring prescriptions to Walmart because they knew that other pharmacies would not accept them.

In the briefing with reporters, DOJ officials declined to comment on why no criminal charges were brought in conjunction with the civil lawsuit announced today though they did not rule out the potential for some to be brought in the future.

In its statement, Walmart says it had 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.” Walmart, aware of the DOJ investigation, sued the DOJ and DEA in October.