The NFL is returning more than $700,000 of taxpayers' money that was paid to teams for sponsored military tributes.

After being criticized for "paid patriotism," in which money came out of the armed forces budget for various measures of public recognition during games, NFL commissioner Roger Goodell said that the league would pay that money back.

In a letter written to Senators Jeff Flake and John McCain on Wednesday, and disclosed on Thursday, Goodell said that -- following an audited review of 100 marketing agreements from 2012 to 2015 by accounting firm Deloitte & Touche -- teams were deemed to have received $723,734 for acts of sponsored patriotism.

That money, Goodell promised, would be returned to the government. Goodell also wrote that marketing activities would be audited more frequently to catch such activities in the future.

The NFL has refunded more than $723,000 to the U.S. government for marketing agreements sponsoring acts of patriotism -- including on-field flag ceremonies and tributes to welcome home veterans -- between 2012 to 2015. Tommy Gilligan/USA TODAY Sports

"In all the years I've spent rooting out egregious federal spending, the NFL is the first organization to perform due diligence, take responsibility and return misspent funds to the taxpayers," Flake said. The NFL's response to this investigation sets a new standard and only strengthens its reputation as a supporter our nation's military service members and veterans."

Last year, Flake and McCain disclosed that the U.S. Department of Defense had spent $5.4 million in contracts with 14 NFL teams from 2011 to 2014. Some of those contracts disclosed that payment was for on-field flag ceremonies and tributes to welcome home veterans. One team, the Atlanta Falcons, had made more than $1 million from the department over those four seasons.

The National Guard, which spent $6.7 million on contracts with NFL teams from 2013 to 2015, dumped its NASCAR sponsorship of Dale Earnhardt Jr.'s car in 2014, after the last four years and more than $100 million spent failed to produce concrete information that the marketing led to more recruits.