The high-risk investment was recommended by Jeffrey Rubin, who operated Pro Sports Financial in Fort Lauderdale, Fla., the South Florida Sun Sentinel reported.
Rubin persuaded the players to put money into the Center Stage Alabama entertainment complex that filed for bankruptcy in January owing $68 million.
Former Baltimore Ravens cornerback Samari Rolle was one of the first to complain to the government.
He told the Financial Industry Regulatory Authority in February 2011 that his investments of millions of dollars "are unaccounted for and inaccessible."
FINRA officials said Rolle lost about $3 million after Rubin made "unsuitable recommendations" to invest in "illiquid, high-risk securities related to the now-bankrupt casino.
Rubin could not be reached for comment but in its statement FINRA said Rubin neither admitted or denied the charges but consented to the authority's findings.
A New York securities fraud attorney said he is looking into whether the companies Rubin was working for at the time can be held responsible for the football players' huge losses.
Current or former NFL players who lost money include Plaxico Burress, Terrell Owens, Roscoe Parrish, Santana Moss, Santonio Holmes, Clinton Portis, Mike Peterson, Duane Starks and Fred Taylor, FINRA documents indicate.