WASHINGTON (Reuters) - The U.S. Congress is moving to shut down a scheme that lawmakers said funneled millions of taxpayer dollars from the Pentagon to professional sports teams for honoring American soldiers at sporting events.

Since 2012, the Pentagon paid out at least $6.8 million in contracts to teams in the National Football League, Major League Baseball, the National Hockey League and Major League Soccer, according to Senate Armed Services Committee Chairman John McCain and his fellow Arizona senator, Jeff Flake.

Dubbing the practice "paid patriotism," the Republican senators found that the Department of Defense had entered into at least 72 contracts with the professional teams to pay for ceremonies in packed stadiums.

Asked at a news conference whether the soldiers being honored were aware that the Pentagon was paying the teams, McCain said: "Obviously they did not know that their appearances were being used in a way that would monetarily benefit the teams that were sponsoring these events."

McCain said a massive military authorization bill moving through Congress will contain a provision prohibiting the Pentagon practice.

According to a report by the two senators, the New York Jets football team received $20,000 from the Pentagon as part of a contract paying to recognize one or two New Jersey Army National Guard soldiers as "hometown heroes" at home games.

"We strongly oppose the use of recruitment funds for anything other than their proper purpose," NFL Commissioner Roger Goodell said in a statement, adding that the league was conducting an audit of all contracts between its teams and the military.

According to the McCain-Flake report, three contracts totaling $450,000 went to the Atlanta Braves baseball team to help pay for a "surprise homecoming" for soldiers, a parade and "patriotic-themed presentations."

The Milwaukee Brewers baseball team received $49,000 for activities including Sunday performances of the song "God Bless America."

Closer to the senators' home, the Arizona Diamondbacks baseball team received $40,000 last year for events including an on-field "oath ceremony" for the Arizona Army National Guard and a color guard demonstration.

That contract also paid for a soldier to deliver a ceremonial "first pitch" to open a baseball game.

McCain, a U.S. Naval Academy graduate who was tortured while being held prisoner during the Vietnam War, is one of the most influential members of Congress.

Nevertheless, he complained that the Pentagon repeatedly hampered the senators' efforts to get information on the "paid patriotism" contracts.

(Additional reporting by Steve Ginsburg; Editing by Doina Chiacu)