Several high-profile athletes, including Denver Broncos quarterback Peyton Manning, have been listed in an undercover probe conducted by Al Jazeera to have received illegal performance-enhancing drugs from an anti-aging clinic in Indiana.

Al Jazeera’s documentary on sports doping reports that a supply of human growth hormone was given to Manning in 2011 while he was recovering from neck surgery as a member of the Indianapolis Colts. The drugs were allegedly provided by Charlie Sly, identified as a pharmacist from the Guyer Institute in Indianapolis.

“The allegation that I would do something like that is complete garbage and is totally made up,” Manning  said in a statement via the Broncos . “It never happened. Never.”

The documentary titled “The Dark Side” states that Sly mailed performance   enhancers,including HGH, to Peyton’s wife Ashley Manning, in order to keep the future Hall-of-Fame quarterback’s name out of the operation.

The NFL and players' union added HGH testing to the collective bargaining agreement signed in 2011, but there was no agreement on the terms of testing until 2014. Nobody has yet tested positive, a result that would trigger a four-game suspension.

"Yes, I have been a patient under Dr. Guyer. I have had nutrient therapy, oxygen therapy and other treatments that are holistic in nature but never HGH,” Manning told ESPN’s Chris Mortensen. “My wife has never provided any medication for me to take.”

Sly told Mortensen that he isn't a pharmacist and wasn't at the Guyer Institute in 2011, as Al Jazeera claimed. State licensing records indicate that a Charles David Sly was licensed as a pharmacy intern in Indiana from April 2010 to May 2013.

In addition, Sly said he was testing Al Jazeera's undercover reporter by using the names of prominent sports stars like Manning. He said he recanted his story to Al Jazeera when he realized that it had used information he had “made up” when speaking with undercover reporter Liam Collins.

"When I realized Al Jazeera was using a secret taping and Collins as a so-called investigative reporter, I was baffled," Sly told ESPN’s Chris Mortensen. "I cannot believe that can happen. That's why I recanted the story. It wasn't true, and I was trying to pull one over on Collins to see if he had any idea of what he was talking about. ”

The report links several other athletes to HGH and other drugs, including Steelers linebacker James Harrison and Packers defensive lineman Julius Peppers. Boxer Mike Tyson and baseball players Ryan Howard and Ryan Zimmerman were also connected to the report in receiving drugs from Sly as was Packers linebacker Clay Matthews, who allegedly received painkillers.