Al Jazeera has released an explosive documentary about the world of performance-enhancing drugs in sports.

“The Dark Side: Secrets of the Sports Dopers,” which hit YouTube early before airing Sunday night, alleges that several high-profile stars, including Peyton Manning, have taken drugs like human growth hormone, otherwise known as HGH.

In the documentary, British hurdler Liam Collins goes undercover, telling medical professionals he’s seeking illegal performance-enhancing drugs in order to make the 2016 Olympic games in Rio.

Clayton Sly, one of Manning’s accusers, tells Collins in the 49 minute doc that the popular NFL quarterback took HGH for a neck injury before he was traded from the Indianapolis Colts to the Denver Broncos.

Sly, who has since recanted his statement, told Al Jazeera that Manning would receive the drugs from an anti-aging clinic in Indianapolis called Guyer Institute, where Sly was an employee.

“(Manning) and his wife would come in after hours and get IVs and s—. So one thing that Guyer does is he dispenses drugs out of his office, which physicians can do in the United States. It’s just not very many of them do it. And all the time we would be sending Ashley Manning drugs. Like growth hormone, all the time, everywhere, Florida. And it would never be under Peyton’s name. it would always be under her name.”

Other sports stars named in “The Dark Side” report are Clay Matthews, Mike Neal and Julius Peppers of the Green Bay Packers, MLB stars Ryan Howard and Ryan Zimmerman, and James Harrison, a linebacker for the Pittsburgh Steelers.

Watch the entire documentary below: