The top executive at McKinsey and Company, appearing before Congress for the first time, came under fire from Democrats. One likened the firm's earnings to blood money from drug traffickers.

The managing partner of McKinsey apologized to the House Committee on Oversight and Reform. He said the firm failed to recognize the broader context of what was going on in society.

The main topic of the hearing was whether McKinsey had a conflict of interest when it was advising the Food and Drug Administration. He insisted that McKinsey had been transparent.

Mr. Sternfels told the committee that McKinley did not serve the F.D.A. and Purdue on Opioid-related matters.

"Your apologies feel empty and insincere," said Representative Ayanna Pressley of Massachusetts.

Some of the most vulnerable people in America were put at risk by McKinsey's work with doctors who were heavy prescribers of painkillers. The work for Purdue began in 2004 and continued for 15 years.

McKinsey agreed to pay $600 million to settle investigations by state attorneys general into its role in helping to increase sales of the drug. The firm was not allowed to take on such work in the future.

Conflicts and conduct at McKinsey are among the worst I have seen in my years in government, said Carolyn Maloney, the New York Democrat who leads the committee.

ImageCarolyn Maloney, chairwoman of the Committee on Oversight and Reform, sharply criticized McKinsey for apparent conflicts of interest.
Carolyn Maloney, chairwoman of the Committee on Oversight and Reform, sharply criticized McKinsey for apparent conflicts of interest.
Carolyn Maloney, chairwoman of the Committee on Oversight and Reform, sharply criticized McKinsey for apparent conflicts of interest.

Cori Bush, a Missouri Democrat, said that they are demanding answers from one of the most evasive and secretive consulting companies in the world.

In one exchange, Tlaib asked Mr. Sternfels why a McKinsey consultant placed a smile on the face of a high-prescribing doctor.

Mr. Sternfels, who took the top post at McKinsey last July, said that a smiley face is completely inappropriate.

At least 22 McKinsey consultants have worked for the F.D.A. since 2010, according to a report released this month by the committee. McKinsey served F.D.A. offices that approved new drugs and monitored their safety, as well as advising on its interactions with the agency. The New York Times reported that McKinsey cited its connections to regulators when seeking more work at pharmaceutical companies.

One consultant stressed in an email to the chief executive that the firm worked for the F.D.A.

On April 5, a group of Senate Democrats sent a letter to the inspector general of the Health and Human Services Department, which oversees the F.D.A., asking for an investigation into possible conflicts of interest arising from McKinsey's work.

McKinsey has taken in more than 140 million dollars in fees from the F.D.A., advising the agency on a wide range of topics.

In a Senate hearing on the F.D.A., Patrizia Cavazzoni, director of the agency's Center for Drug Evaluation and Research, said that the agency would not.

ImageMaura Healey, the Massachusetts attorney general, said McKinsey had made $86 million from advising the maker of OxyContin.
Maura Healey, the Massachusetts attorney general, said McKinsey had made $86 million from advising the maker of OxyContin.
Maura Healey, the Massachusetts attorney general, said McKinsey had made $86 million from advising the maker of OxyContin.

Ms. Healey said that McKinsey had a conflict of interest in working with the F.D.A. She referred to internal documents showing McKinsey's relationship with the F.D.A.

The documents McKinsey handed over to Ms. Healey's office show how much McKinsey made from advising Purdue.

He said he was happy to dig that up and come back to the committee. She asked Ms. Healey how much she was worth.

Ms. Maloney said she would introduce legislation to require more stringent standards for the agency that oversees conflicts of interest in federal contracting. The bill was introduced in the Senate.

Representative Connolly, a Virginia Democrat, inquired about a slide from a presentation McKinsey had prepared for Purdue. A system of incentives for sales representatives included a cash prize and celebrity status, with images of Donald J. Trump.

ImageIn 2013, McKinsey advised Purdue Pharma, an opioid maker, on how to incentivize its sales representatives.
In 2013, McKinsey advised Purdue Pharma, an opioid maker, on how to incentivize its sales representatives.Credit...no credit
In 2013, McKinsey advised Purdue Pharma, an opioid maker, on how to incentivize its sales representatives.

600,000 Americans are dead, according to Mr. Connolly. Do you want to tell the committee about your regrets?

I regret that we didn't act sooner, sir. I would have put the client protocols in a decade earlier if I could play this over. I would have reached a settlement even faster, and we would have pivoted from serving the manufacturers despite the goals there were, and I apologized for that.

Ms. Tlaib was not satisfied with McKinsey's work and compared it to that of drug traffickers.

While McKinsey was celebrating its blood money, communities were being torn apart.

The Republicans on the committee did not play a role in questioning Mr. Sternfels. They said the hearing should have focused on the issue of the trafficking of Fentanyl across the southern border.