From 2006 to 2015, federal lawmakers from Connecticut received at least $665,000 in contributions from participants in the Pain Care Forum, a little-known group of pharmaceutical companies, trade groups and nonprofits.

Most of Connecticut's current congressional delegates said they were not familiar with the group, whose participants spent more than $740 million from 2006 through 2015 in lobbying expenses at the state and federal levels to advocate for a variety of issues, including keeping opioids accessible, according to a recent investigation by the Associated Press and Center for Public Integrity.

The group's legislative interests are, of course, not limited to opioids, and there's no way to tell how much of the group's spending was directly tied to influencing opioid laws.

The AP and CPI investigation used a variety of data sources including Federal Election Commission records, and contributions that have come from the treasury of a company or organization, political action committees, and employees.

Participants in the Pain Care Forum were determined by examining membership directories, which the Center for Public Integrity obtained, from 2006 through 2013. But it's unclear from the investigation which members are still active today or their level of participation.

The group meets monthly in Washington to discuss public policy issues surrounding pain care.

Connecticut's congressional delegation all voted in favor of the Comprehensive Addiction and Recovery Act, signed by the president in July that seeks to curb heroin and prescription opioid abuse. President Obama had asked Congress for more than $1 billion in spending for the new programs, but the bill only authorizes $181 million.

U.S. Rep. Joe Courtney, D-2nd District, received at least $160,000 in contributions from Pain Care Forum participants, according to AP and CPI data. Of that, 38 percent came from Pfizer whose 160-acre research site in Groton is in the Second Congressional District, which Courtney has served since 2007.

Courtney's spokesman Tim Brown said the congressman is not aware of the Pain Care Forum, and that "he remains focused on leading a bipartisan effort to ensure that those on the front lines responding to the opioid crisis have the support and resources they need."

"As he has said all along, this is a public health emergency that requires 'all hands on deck,' from changes in the way opioids are marketed and prescribed, to expanding the infrastructure to care for those seeking to break free from the cycle of addiction," Brown said in a statement.

While U.S. Sen. Chris Murphy, D-Conn., received at least $85,000 in contributions from 2007 to 2015, his spokeswoman Laura Maloney said that none of them came from pharmaceutical companies or their PACs. Instead contributions that Murphy received from Pfizer and Purdue Pharma came from their employees.

"Chris doesn't accept donations from drug company political action committees, but ultimately, he believes that campaign finance reform is the only way to lessen the power of big corporations on the political process," Maloney said in a statement. "In the meantime, he will keep fighting to lower drug costs through policies like allowing the federal government the force down the cost of drugs through bulk negotiation -- one of the many policies he supports that the drug industry opposes but is the right thing to do for consumers."

Murphy told Morning Consult earlier this year that everybody needs to "pony up money" to address the opioid crisis, and specifically named the federal government, states, the medical profession and the drug industry.

Murphy served Connecticut's Fifth Congressional District from 2007 to 2013, and has served as senator since 2013.

U.S. Sen Richard Blumenthal, D-Conn., received at least $70,800 between 2010 and 2015. He has served since January 2011. Before that he served five terms as Connecticut's Attorney General.

"His legal action as Attorney General and aggressive advocacy in the United States Senate have put him at the forefront of the battle against sales practices and deception by the pharmaceutical industry that contributed significantly to our country's opioid crisis," his spokeswoman Maria McElwain said in a statement.

"Most recently, his aggressive advocacy has involved roundtables with hundreds of first responders, law enforcement leaders, addiction recovery experts and individuals personally affected by opioid abuse—powerful public discussions held in communities across Connecticut," McElwain's statement said.

U.S. Rep. Jim Himes, D-4th District, and U.S. Rep. John Larson, D-1st District, received around the same level of contributions from participants of the Pain Care Forum.

Himes, who has served the fourth district since 2009, received at least $135,000 from 2007 to 2015.

Himes' spokesman Patrick Malone said in a statement that the congressman "always puts his constituents' interests first and foremost."

"Occasionally, drug companies agree with his positions. Often they do not. For example he supports efforts to reduce drug costs for seniors and families, wants to make generics more readily available, and pushed back against the industry in recent trade negotiations over the (Trans-Pacific Partnership trade deal). The scourge of opioids is tearing families and communities apart, and he's doing everything he can to provide the necessary funding and training to combat it," Malone's statement said.

Malone said he did not know if Himes is familiar with the Pain Care Forum.

Larson, who has served in Congress since 1999, received at least $137,000 between 2006 and 2015. His office did not respond to a request for comment before publication.

U.S. Rep. Elizabeth Esty, D-5th District, received at least $38,500 between 2011 and 2015.

Esty has served since in Congress since 2013, and her spokesman Craig Frucht said that "she's developed a comprehensive legislative agenda for dealing with the crisis, and none of it has been driven by lobbying or politics."

"It's been driven by her conversations here in Connecticut with addiction experts, physicians, patient advocates, and families who have experienced addiction firsthand," Frucht said in a statement. "Those conversations led her to introduce the Prevent Drug Addiction Act earlier this year, and she was proud that President Obama signed portions of that bill into law this summer as part of a comprehensive, bipartisan measure to tackle the crisis."

He did not say whether Esty is familiar with the Pain Care Forum.

U.S. Rep. Rosa DeLauro, D-3rd District, whose spokesman said she was not familiar with the Pain Care Forum, received at least $34,200 from its participants between 2006 and 2015. DeLauro has served in Congress since 1991.

Her spokesman Ron Boehmer said in a statement that the congresswoman "has fought for additional funding to end this epidemic, introduced the Access to Substance Abuse Treatment Act to provide $1 billion a year to provide prevention and treatment for substance abuse, and has met regularly with recovering addicts, families, physicians, law enforcement, and community leaders."

j.bergman@theday.com