The families of dozens of U.S. troops killed or injured during the war in Iraq filed a federal lawsuit Tuesday against several U.S. and European pharmaceutical and medical supply companies, alleging that the corporations knowingly financed the anti-American militia Mahdi Army through bribes and kickbacks to officials at a government ministry controlled by the group.

The lawsuit in U.S. District Court in Washington, D.C., against some of the biggest names in the industry — including GE Healthcare, Johnson & Johnson, Pfizer, AstraZeneca and Roche Holdings — claims that the companies regularly paid kickbacks to officials in Iraq’s Ministry of Health through their local agents.

Officials at the ministry in turn used the proceeds to help fund the militia that carried out attacks against U.S. troops in Iraq, the suit alleges.

In the aftermath of the 2003 invasion, Iraq’s health care spending surged, and the Health Ministry’s budget ballooned from $16 million during Saddam Hussein’s final year in power to about $1 billion in 2004.

Western companies looking to break into the Iraq market were willing to pay kickbacks — billed as “commissions” or “free goods” — that amounted to as much as 20% of the value of a contract to ministry officials, the lawsuit alleges.

Another way the defendants allegedly made the illegal payments was by including language in the contracts promising after-sales support and other services related to the product they sold and funded those services by giving money to their local agents.

"In reality, such services were illusory and functioned merely to create a slush fund the local agents could use to pass on 'commissions to corrupt (ministry) officials,'" the lawsuit alleges.

The plaintiffs charge that through the transactions the companies aided and abetted the militants, violating the U.S. anti-terrorism act.

Pfizer responded to the lawsuit in a statement, saying the company "categorically denies any wrongdoing,” while GE said in a statement it was "thoroughly reviewing the allegations.” A spokeswoman for Roche said the company had not yet been served with the lawsuit and declined comment.

Representatives from AstraZeneca and Johnson & Johnson did not respond to requests for comment.

By 2005, the ministry came under the control of loyalists of Muqtada al-Sadr, an Iranian-backed cleric. Al-Sadr's political clout grew amid dissatisfaction among some Iraqis over the U.S. military presence and sectarian fighting among the country’s majority Shiite and minority Sunnis populations.

Backers of al-Sadr in the Mahdi Army — also known as Jaysh al-Mahdi and JAM — killed and injured hundreds of American troops in the years-long insurgency in the aftermath of the invasion.

“Defendants did not intend for the ‘free goods’ provided to Kadima (health ministry’s pharmaceutical importing agency) to serve any legitimate charitable or medicinal purpose,” the lawsuit alleges. “It was widely understood in Iraq that MOH (Ministry of Health) operated more like a terrorist organization than a legitimate health entity, and no rational company would have viewed MOH as a suitable object for charity.”

U.S. officials in Iraq expressed concern that the Health Ministry was beset by corruption and had become a Sadr fiefdom. News reports about pharmaceuticals flooding the black market suggested that Sadr backers were using the ministry to bankroll the Mahdi Army.

By late August 2007, a draft of an alarming U.S Embassy Baghdad report had become public that accused the ministry of “operating a pharmaceutical diversion scheme” and of being “openly under the control of the Mahdi Army.”

Months before the embassy report, the global intelligence company Stratfor — which provided advisory reports to senior executives at several of the companies named as defendants in the suit — noted in a briefing for its subscribers that U.S.-led forces in Iraq had arrested the then-deputy health minister for “selling health services and equipment in return for millions of dollars that he later funneled to Shiite militias.”

The Iraq war victims' lawsuit comes amid greater scrutiny of global brands' efforts to win favor with politicians and policymakers.

In August, Lee Jae-yong, the third-generation heir to the Samsung empire, was sentenced to five years in prison for paying nearly $8 million in bribes to win the support of South Korean President Park Geun-hye for a complex corporate deal. Wal-Mart is still dealing with the fallout of a 2012 New York Times report that it paid millions of dollars in suspect payments to government officials in Mexico to help speed up construction of stores there.

Last month, a federal judge in Arkansas ruled that a class-action lawsuit brought by a Michigan pension fund alleging that shareholders were defrauded by company executives could move forward. The City of Pontiac Employees’ Retirement System argues that Wal-Mart officials failed to properly investigate bribery claims that they were first reportedly made aware of in 2005.

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Al-Sadr was born into a family of Shiite scholars, the son of the Grand Ayatollah Mohammad Sadaq al-Sadr, a highly influential cleric who was assassinated along with two of his sons in 1999 during Saddam's rule. Muqtada al-Sadr went into hiding until the U.S. invasion and later drew much of his power from those living in the slums of Baghdad, Sadr City, which was named for his father.

Posters of the younger al-Sadr and his martyred father lined the walls of the Health Ministry. The younger cleric drew tens of thousands to his rallies and Friday sermons in which he spoke out against the U.S. presence in Iraq after Saddam’s ouster.

Attorneys for the plaintiffs from the Washington, D.C.-based law firms of Sparacino & Andreson and Kellogg, Hansen, Todd, Figel & Frederick said they spent thousands of hours investigating and analyzed hundreds of transactions between the defendants and Health Ministry between 2004 and 2013.

Ami Neiberger-Miller, a plaintiff whose 22-year-old brother, Army Spc. Christopher Neiberger, was killed in a roadside bombing allegedly carried out by the Mahdi Army in Baghdad in August 2007, said her family wants the companies to be held accountable.

"I had always pictured by brother's killers as faceless," said Neiberger-Miller, who recalled her younger brother as funny and a good friend. "I wouldn't have thought U.S. companies would have anything to do with his death. Those funds went directly from those companies to terrorists who had a mission to kill U.S. troops like my brother. They should be held accountable. Companies should know what is done in their name.

The plaintiffs’ attorneys said the alleged bribery scheme was a continuation of how some of the companies and their affiliates named in the suit conducted business during the final years of Saddam’s rule.

Hundreds of multinational companies are alleged to have funneled more than $1.7 billion into Saddam’s regime, skirting sanctions by abusing the U.N. Oil-for-Food program that was designed to soften the impact on the Iraqi people by allowing the supervised sale of some Iraqi oil for food, medicine and other necessities.

In 2010, GE resolved a Foreign Corrupt Practices Act charge brought by the U.S. Securities and Exchange Commission by paying almost $23 million in fines. Two GE subsidiaries were alleged to have obtained at least four medical-goods contracts between 2000 and 2003 by agreeing to “pay illegal kickbacks in the form of computer equipment, medical supplies and services” to the Kimadia, the Health Ministry’s purchasing agency, the lawsuit notes.

AstraZeneca AB, the pharmaceutical behemoth’s UK-affiliate, paid at least $162,000 in kickbacks as part of the sale of $1.7 million of drugs under the sanctions relief program, according to the Volcker Committee, the panel that investigated the alleged corruption in the Oil-for-Food program.

“We believe that the evidence will show that when Jaysh al-Mahdi seized the Iraqi Health Ministry, the defendants continued paying the same bribes they provided under Saddam — except in far greater amounts," said Ryan Sparacino, one of the attorneys representing plaintiffs in the lawsuit.