The Ohio medical board concluded that pain physician William D. Leak had performed unnecessary nerve tests on 20 patients and subjected some to "an excessive number of invasive procedures.'' Yet the finding, posted on the board's public website, did not prevent Eli Lilly and Co. from using him as a promotional speaker and adviser.

In 2001, the US Food and Drug Administration ordered Pennsylvania doctor James I. McMillen to stop "false or misleading'' promotions of the painkiller Celebrex, saying he minimized risks and touted it for unapproved uses.

Still, three other drug makers have paid the rheumatologist $224,163 since 2009 to deliver talks to other physicians about their drugs.

In Georgia in 2004, a state appeals court upheld a hospital's decision to kick Dr. Donald Ray Taylor off its staff. The anesthesiologist had admitted giving young female patients rectal and vaginal exams without documenting why. When confronted by a hospital official, Taylor said, "Maybe I am a pervert, I honestly don't know,'' according to the court ruling.

Last year, Taylor was the third-highest-paid speaker for Cephalon, receiving $142,050 in 2009 and another $52,400 through June.

Drug companies say they hire the most respected doctors in their fields for the critical task of teaching about the benefits and risks of their drugs. But an investigation by ProPublica uncovered hundreds of doctors on company payrolls who had been accused of professional misconduct, were disciplined by state boards, or lacked credentials as researchers or specialists.

A review of physician licensing records in the 15 most populous states and three others found sanctions against more than 250 speakers, including some of the highest paid. Their misconduct included inappropriately prescribing drugs, providing poor care, or having sex with patients. Some of the doctors had even lost their licenses.

More than 40 have received FDA warnings for research misconduct, lost hospital privileges, or been convicted of crimes. And at least 20 more have had two or more malpractice judgments or settlements. This accounting is by no means complete; many state regulators do not post these actions on their websites.

Five disciplined Massachusetts doctors appeared on the list. Their sanctions included engaging in "disruptive behavior with patients and other medical staff,'' a lack of sensitivity during physician exams, and improperly peeking into employees' medical records. They earned between $3,250 and $18,000 since 2009 from the seven companies that have disclosed payments.

The implications are great for patients, who in the past have been exposed to such heavily marketed drugs as the painkiller Bextra and the diabetes drug Avandia, which were billion-dollar blockbusters until dangerous side effects emerged.

"Without question, the public should care,'' said Dr. Joseph Ross, an assistant professor of medicine at Yale School of Medicine who has written about the industry's influence on physicians. "You would never want your kid learning from a bad teacher. Why would you want your doctor learning from a bad doctor, someone who hasn't displayed good judgment in the past?''

There is much debate about whether paying doctors to market drugs can inappropriately influence what they prescribe. Studies have shown that even small gifts and payments affect physician attitudes.

To vet the industry's handpicked speakers, ProPublica created a comprehensive database that represents the most accessible accounting yet of payments to doctors. Compiled from disclosures by seven companies, the database covers $257.8 million in payouts since 2009 for speaking, consulting, and other duties.

All told, 384 of the approximately 17,700 individuals in the database earned more than $100,000 from one or more of the seven companies in 2009 and 2010. Nearly all were physicians, but a handful of pharmacists, nurse practitioners, and dietitians also made the list. Forty-three physicians made more than $200,000, including two who topped $300,000. In addition to Lilly and Cephalon, the companies include AstraZeneca, GlaxoSmithKline, Johnson & Johnson, Merck & Co., and Pfizer.

Leak, whom Lilly has paid $85,450 since 2009, and his attorney did not respond to multiple messages. The Ohio medical board voted to revoke Leak's license in 2008. It remains active as he appeals in court, arguing that the evidence against him was old, the witnesses unreliable, and the sentence too harsh.

McMillen denied nearly all of the allegations in the FDA letter. "I'm more cautious now than I ever was,'' he said. "That's why I think a lot of the companies use me.''

Taylor said that the allegations against him were "old news'' from the 1990s, and that regulators had not sanctioned him. "It had nothing to do with my skills as a physician,'' said Taylor, noting that he speaks every other week around the country and sometimes abroad.