In its latest effort to confront what it sees as misinformation, UnitedHealth Group has filed a defamation lawsuit against the Guardian over a May news story that asserted the Eden Prairie-based health company grew its profits and harmed patients by slashing nursing home transfers to hospitals.

In the lawsuit filed this week in a Delaware court against the international news publication, UnitedHealth said the article contained numerous false accusations. Among them: The health care company secretly paid nursing homes to enroll patients in UnitedHealthcare insurance and then coerced residents to sign do-not-resuscitate (DNR) orders, preventing costly hospitalizations and lifesaving treatments.

The Guardian said in a statement that it stands by its story.

The lawsuit claims the news organization relied partly on "intentionally deceptively doctored documents" to support its claims.

According to the suit, the documents included an internal UnitedHealth Group email that was misleadingly cropped to exclude messages about how workers should comply with industry standards and help residents make informed decisions without making signed DNRs the goal.

"This is unquestionably defamatory. The Guardian effectively accuses UnitedHealth of intentionally causing the premature deaths of patients by fraud," the suit says. "Such an accusation could not be more serious. And it could not be more false."

The Guardian said its reporting was factual, based on thousands of corporate and patient records, publicly filed lawsuits, declarations submitted to federal and state agencies, and interviews with more than 20 current and former UnitedHealth employees.

The news organization said the story also incorporated statements and information provided by UnitedHealth itself over several weeks.

"It's outrageous that in response to factual reporting on the practice of secretly paying nursing homes to reduce hospitalizations for vulnerable patients, UnitedHealth is resorting to wildly misleading claims and intimidation tactics via the courts," the Guardian said.

The day the investigative report was published, shares of UnitedHealth Group lost 6% of their value.

It was the latest blow to the share price amid financial missteps by the company, an abrupt CEO change and a Wall Street Journal report in May revealing a criminal fraud investigation related to its business practices in the Medicare Advantage program.

The lawsuit against the Guardian is another example of UnitedHealth Group more aggressively confronting what the company regards as misinformation.

Earlier this year, the company engaged in a protracted public dispute with a surgeon in Texas and a prominent activist investor that included company demands for them to remove social media posts related to why the doctor felt she had to leave the operating room one day to argue for coverage.

The lawsuit seeks financial damages, plus an injunction to remove, retract and prevent republication of any statements the court decides are defamatory.

The request for an injunction is significant because they're seldom sought or granted in libel cases, said Jane Kirtley, a professor of media ethics and law at the University of Minnesota.

The broader goal of the lawsuit "certainly could, in part, be a warning to other news media, not to engage in close investigation of UnitedHealthcare," Kirtley said.

"That certainly is one of the reasons that companies file lawsuits like this, to discourage others from pursuing similar lines of inquiry."

If the litigation ever reaches the damages phase, Kirtley questioned whether UnitedHealth would be able to show a connection between the Guardian's report and purported business and reputational harms, given the publication's somewhat limited reach in the U.S. and other challenges facing the company.