McKinsey & Company consulting firm has agreed to pay $650 million to settle a federal investigation into its work for opioids manufacturer Purdue Pharma, according to court papers filed in Virginia on Friday.

McKinsey has also entered into a deferred prosecution agreement to resolve criminal charges, including that it conspired with Purdue Pharma to aid in the misbranding of prescription drugs.

A former McKinsey senior partner has also agreed to plead guilty to obstruction of justice, according to the court papers.

McKinsey representatives didn’t immediately respond to phone and email messages on Friday.

Since 2021, McKinsey has agreed to pay state and local governments about $765 million in settlements for its role in advising businesses on how to sell more of the powerful prescription painkillers amid a national opioid crisis.

The consulting firm also agreed last year to pay health care funds and insurance companies $78 million.

The U.S. has been in an addiction and overdose crisis for decades, linked to more than 80,000 deaths in recent years. For the past decade, most of the deaths have been attributed to illicit fentanyl, which is laced into many illegal drugs. Earlier in the epidemic, prescription pills were the primary cause of death.

Some advocates say the crisis was touched off when Purdue Pharma’s OxyContin hit the market in 1996.

Three Purdue executives pleaded guilty to misbranding charges in 2007 and the company agreed to pay a fine. The company pleaded guilty to criminal charges in 2020 and agreed to $8.3 billion in penalties and forfeitures — most of which will be waived as long as it executes a settlement through bankruptcy court that is still in the works.

McKinsey documents made public over the years describe Purdue using the consulting firm to help “turbocharge” opioid sales in 2013, as blowback against the opioid crisis meant that the company’s drugs were being prescribed less.

___

Mulvihill reported from Philadelphia.