Washington: Major League Baseball and the National Football League will investigate allegations in an Al Jazeera documentary that employees at an Indianapolis-based anti-aging clinic supplied performance enhancing drugs to a host of professional athletes including legendary quarterback Peyton Manning and Washington Nationals first baseman Ryan Zimmerman.

The report, due to air on Sunday night, used information it said was gathered by an undercover reporter who was actually a former athlete, Liam Collins, a British hurdler. It elicited a series of denials from all corners - not only from several of the athletes named but from one of the primary sources of the film’s information.

Charlie Sly, who the report refers to as a pharmacist who worked with the Indianapolis-based Guyer Institute of Molecular Medicine, makes claims to Collins in the documentary that he helped treat Manning during his recovery from a neck injury in 2011. Collins secretly recorded his conversations with Sly, using hidden cameras to film discussions in which Sly also implicated Zimmerman, Philadelphia Phillies first baseman Ryan Howard and NFL defensive stars Julius Peppers of the Green Bay Packers and James Harrison of the Pittsburgh Steelers in the use of performance enhancing drugs.

But on Sunday, Sly posted a video on YouTube in which he recanted the information he told Collins.

“The statements on any recordings or communications that Al Jazeera plans to air are absolutely false and incorrect,” Sly said on the video.

Dale Guyer, the founder and medical director of the Guyer Institute, also issued a statement disputing the information Sly gave to Collins. In an email, Guyer said Sly was an unpaid intern who worked for three months at the Indianapolis clinic not in 2011, as the report claimed, but in 2013, after Manning had moved on to Denver to join his current team, the Broncos. The statement called Sly’s claims “callous and destructive.”

I have no reason to believe these allegations are based in fact or have any truth,” Guyer wrote. “In fact, I can say with absolute certainty they are not.”

The Al Jazeera report, though, was enough to get the attention of officials from both MLB and the NFL. According to officials in both leagues, it is typical for such reports to spur investigations. Both leagues have established arms that handle such investigations.

The information in the Al Jazeera documentary - which included claims that Manning used human growth hormone and that Zimmerman was one of several athletes who used a hormone supplement known as Delta-2 - was new to the leagues this weekend, officials said.

“We intend to conduct a thorough investigation,” a spokesman for MLB said.

In the meantime, Manning and others began their self-defense. Manning issued a personal statement, received the backing of both his current team - the Broncos - and the one he played for at the time of the alleged HGH use - the Indianapolis Colts - and went on ESPN to flatly deny the contents of the report.

“For the record, I have never used HGH,” Manning said. “It absolutely never happened. The whole thing is totally wrong.”

HGH has long been on the NFL’s list of banned substances, but testing did not take effect until 2014 after protracted haggling over the details of the testing program. MLB began blood tests for HGH in 2012.

Sly named Zimmerman, the Nationals’ longest-tenured player, and Howard as players who received Delta-2. An attorney for the pair issued a statement early Sunday.

“The extraordinarily reckless claims made against our clients in this report are completely false and rely on a source who has already recanted his claims,” attorney William Burck said.

The Nationals also issued a statement questioning the credibility of the report and calling Zimmerman “the model for all we ask our players to be.”