A scientific panel that shaped the federal government’s policy for testing the safety and effectiveness of painkillers was funded by major pharmaceutical companies that paid hundreds of thousands of dollars for the chance to affect the thinking of the Food and Drug Administration, according to hundreds of e-mails obtained by a public records request.

The e-mails show that the companies paid as much as $25,000 to attend any given meeting of the panel, which had been set up by two academics to provide advice to the FDA on how to weigh the evidence from clinical trials. A leading FDA official later called the group “an essential collaborative effort.”

Patient advocacy groups said the electronic communications suggest that the regulators had become too close to the companies trying to crack into the $9 billion painkiller market in the United States. FDA officials who regulate painkillers sat on the steering committee of the panel, which met in private, and co-wrote papers with employees of pharmaceutical companies.

The FDA has been criticized for failing to take precautions that might have averted the epidemic of addiction to prescription drugs including Oxycontin and other opioids.

“These e-mails help explain the disastrous decisions the FDA’s analgesic division has made over the last 10 years,” said Craig Mayton, the Columbus, Ohio, attorney who made the public records request to the University of Washington. “Instead of protecting the public health, the FDA has been allowing the drug companies to pay for a seat at a small table where all the rules were written.”

Even as the meetings were taking place, the idea of FDA officials meeting with firms that had paid big money for an invitation raised eyebrows for some. In an e-mail to organizers, an official from the National Institutes of Health worried whether the arrangements made it look as if the private meetings were a “pay to play process.”

FDA officials did not benefit financially from their participation in the meetings, the agency said. But two later went on to work as pharmaceutical consultants and more than this, the critics said, the e-mails portray an agency that, by allowing itself to get caught up in a panel that seemed to promise influence for money, had blurred the line between the regulators and the regulated.

In a statement, the FDA said “we take these concerns very seriously.” But, it said, “we are unaware of any improprieties” associated with the group.

Douglas Throckmorton, a deputy director of the agency, said in an interview that strict rules of transparency and funding apply to the public-private partnerships that the agency engages in and that these efforts are important for the government and the industry.

But the group in this case was not initiated by the FDA, he said, and so was a private partnership to which those rules did not apply.

“There are rules in place for us to have these discussions,” Throckmorton said. This group “was set up as a private group.”

The group was organized by two medical professors, Robert Dworkin of the University of Rochester and Dennis Turk of the University of Washington, and the e-mails for the most part describe their efforts at financing and organizing the group’s meetings.

The two professors received as much as $50,000 apiece for a meeting, money that went to their academic research accounts and paid for research assistants and expenses “or to cover a small percentage of faculty effort,” they said. At one point in the e-mails, they proposed that they receive honoraria of $5,000 apiece for a four-hour meeting at a hotel near the FDA offices.

The meetings, typically held around the Washington metropolitan area, focused on the best methods for measuring the effectiveness of painkillers.

“The intent was to help everybody develop better drug trials,” Dworkin said in a phone interview. He and Turk responded to questions via e-mail, as well. A spokeswoman for Pharmaceutical Research and Manufacturers of America, an industry group, declined to comment, saying the organization was unfamiliar with the e-mails.

Exactly how to judge when a painkiller is effective has been a long-running problem for drug companies that believe that some of their products are effective but that their benefits are missed in standard clinical drug trials.

One goal of the group was to design clinical trials that would illuminate the benefits of new drugs that might be missed in standard tests, avoiding what the academics called “false negatives.”

The meetings, which involved about 30 to 40 people, included academics, FDA and NIH officials, and often as many as 14 representatives from pharmaceutical companies. Only the companies paid fees to attend.

Dworkin said the scientific guidelines the group produced were of high quality and that “we are not aware of a single negative comment that has been published.” The goal of the group was to publish “consensus” statements on scientific matters related to testing the drugs.

Bob Rappaport, the chief of the FDA’s analgesic division and an attendee at many meetings of the group, did not respond to e-mails or phone calls.

But he has touted the influence of the group, known by the acronym IMMPACT. A 2007 ­PowerPoint presentation he put together was called “The Impact of IMMPACT” and recognizes the group’s influence on FDA thinking. The presentation describes the committee as “a wealth of opportunity for communication” that was advancing the science and “approving new analgesic drug products.”

While science was the subject of the meetings, the subject of money runs through the e-mails.

Even for a pharmaceutical company, the $20,000 price for an invitation to a Washington meeting seemed high.

When some drug companies balked at the fee, the organizers of the meeting, Dworkin and Turk, were firm.

“20k is small change, and they can justify it easily if they want to be at the table,” Dworkin wrote to Turk in July 2003, after an Eli Lilly representative bridled at the price. “Everybody has been very happy with [the meetings] and they are getting a huge amount for very little money (impact on FDA thinking, exposure to FDA thinking, exposure to academic opinion leaders and their expertise, journal article authorship, etc.) and they know it.”

“Do they really expect it to be any less than 20K per meeting for all this?” Dworkin wrote.

At another point, a company representative called to say that he could come up with $10,000 to attend and was “trying to find more,” as Dworkin told Turk in the e-mail.

“He didn’t realize we were inflexible on the 25k, and then asked, a bit testily, how many companies were already on board and when I said 10 he then asked whether it costs 250K to hold a meeting in DC,” Dworkin wrote. “I gave our standard response to this, which appeared to mollify him fine.”

And in another: “The native(s) is (are) restless regarding finances for IMMPACT,” Turk tells Dworkin in late 2002.

“I don’t know how we will bury the post doc funds if we are too specific,” Turk says in another.

In the interview, Dworkin said that the costs of running such a meeting could run as high as $150,000, and because they never knew how many sponsors they could attract, it was difficult to know where to set the price. To make its gatherings more transparent, the group posted to its Web site copies of meeting presentations.

Even so, at least a few of the government officials attending the meetings seemed to be nervous about appearances.

At one point, an NIH staffer indicated that given the fees paid by drug companies, as well as that the meetings were private, IMMPACT could be criticized because it was “paid for by a few large pharmaceutical firms who are assumed to be influencing the outcomes.”

The NIH staffer suggested holding the meetings on the NIH campus and opening the meeting to all interested parties to “avoid the stigma that this initiative is a ‘pay to play process.’ ”

Dworkin responded in an e-mail: “It is difficult to imagine how an open meeting would develop consensus recommendations.”