Minnesota is suing Purdue Pharma, the manufacturer of the narcotic painkiller OxyContin, following a prolonged investigation into its marketing and other tactics that allegedly contributed to a rising number of patient addictions and overdose deaths.

The lawsuit, filed Monday by state Attorney General Lori Swanson in Hennepin County District Court, seeks to recoup money lost by Minnesota taxpayers in paying for opioid painkillers for unproven and harmful purposes. Modeled after successful efforts to sue tobacco companies for the harm cigarettes caused, Swanson said she hopes to gain money from Purdue to fund treatment of addicts.

“This company misrepresented and minimized the addictive nature of its drugs in order to sell more of them,” she said.

Swanson accused the pharmaceutical company of launching or promoting research suggesting that OxyContin was not addictive, bankrolling organizations to promote that message, falsely claiming that the drug worked for 12 hours and had no dose limit, and blaming patients rather than the drug itself for their addictions.

Deaths linked to legal opioid painkillers such as OxyContin, and illicit forms such as heroin, increased in Minnesota from 54 in 2000 to 401 in 2017, according to the Minnesota Department of Health.

A Purdue spokesman criticized Swanson for filing suit and pursuing a “costly and protracted litigation process” amid ongoing negotiations with multiple states, including Minnesota, in federal court.

“We will continue to work collaboratively with the states toward bringing meaningful solutions to help address this public health crisis,” the spokesman said in a written statement.

Minnesota’s prescribing rate of opioid painkillers has been among the lowest in the nation, and it has declined in recent years through a variety of efforts, including the state Board of Pharmacy’s monitoring activities to identify addicts who were “doctor shopping” for prescriptions, and doctors who were overprescribing to their patients.

But an epidemic started by prescription painkillers has morphed into one fueled by illicit heroin, and by legal and illicit forms of fentanyl — a powerful synthetic that was implicated in the overdose death of pop star Prince. The number of opioid-related fatalities increased in 2017, even though deaths linked to common painkillers declined, because deaths linked to fentanyl and related synthetics increased from 99 in 2016 to 172 last year.

Swanson, a DFL candidate for governor, said she filed the lawsuit because she was unhappy with the pace of negotiations in federal court.