Ex-Broncos LB Says Team Was Cheating By Filming Opponent Practices During McDaniels Era

Ex-NFL linebacker D.J. Williams is opening up about his time with the Denver Broncos and Josh McDaniels ... saying the only reason they were successful is because they were cheating.

Williams made the controversial statement during an interview on the "I AM ATHLETE" podcast with former NFL players Brandon Marshall, Chad Ochocinco, and LeSean McCoy ... saying the Broncos' hot start in 2009 wasn't as dominant as it looked on paper.

In the clip, Williams says he was never more prepared for a football game than during the time he played for McDaniels ... and as he continued talking, he alluded to the main reason why they were so on-point.

"Josh would lay out keys to victory on how we win the game," Williams said. "Every time we did exactly what he said, we won."

Williams said the team executed McDaniels' "strategies" to a T -- and they worked, as the Broncos started off 6-0 that season.

But, the wins weren't piling up because of McDaniels' predictive game-planning ... as Williams claims, there was some constant rule-breaking going on.

"We did that for six weeks. We get to San Francisco and we end up losing. We was supposed to beat San Francisco."

"Our film guy got caught because we had to share a stadium [in London]. Our film guy got caught filming their practice."

McDaniels was later fined $50,000 for failing to report the violation to the league ... and was eventually fired the next season after a poor start.

Of course, McDaniels is no stranger to controversy -- the current Patriots offensive coordinator was in the same role on Bill Belichick's staff when the org. got busted for "Spygate" in 2007.

D.J. firmly believes that the Broncos were only winning games thanks to what he calls "Junior Spygate" ... citing that after their camera guy got fired, they lost 6 of their last 8 games.

"We was having breakfast, like, 'Damn, we not that good.'"

"We was cheating!!!"