(CBSSports) An upcoming Al Jazeera investigative report airing Sunday is linking Peyton Manning to the use of human growth hormone, according to the Huffington Post.

The Huffington Post received an advance screening of a documentary named The Dark Side set to premiere Sunday and, according to their story, a pharmacist named Charlie Sly claims drugs were sent to the Mannings "all the time" addressed to Peyton's wife, Ashley, while Peyton Manning was recuperating from neck surgery in 2011. Manning missed that entire season and was released by the Colts the following spring.

“All the time we would be sending Ashley Manning drugs,” Sly says in the video. “Like growth hormone, all the time, everywhere, Florida. And it would never be under Peyton's name, it would always be under her name.”

According to the Huffington Post, Manning's agent vehemently denied the report, claiming Manning "has never done what this person is suggesting" and stating any medical treatment Manning got was via his doctors.

“The treatment he received at the Guyer Institute was provided on the advice of his physician and with the knowledge of team doctors and trainers."

According to the Huffington Post, Manning's agent did not deny any rumors of Ashley Manning receiving medicine through the mail.

“Any medical treatment received by Ashley is a private matter of hers, her doctor, and her family,” the agent said.

One of the pharmacists involved in the documentary claims he can turn an average human into a world-class athlete through the use of his mailed medicinals.

“No one's got caught, because the system's so easy to beat,” Robertson, the pharmacist, brags to Collins. “And it still is, that's the sad fact. I can take a guy with average genetics and make him a world champion.”

The allegations in the documentary are, quite obviously, shocking. It remains to be seen what the official response from the Broncos quarterback and his camp -- along with the rest of the athletes involved -- will be, but this documentary could strike a note on the outer edges of the sports world.

In addition to Manning, the report also names a few Packers players. According to the Huffington Post and Al Jazeera's documentary Packers linebacker Mike Neal has taken Delta-2, a hormone supplement, and connected Julius Peppers with the drug.

The report does not link Manning to Delta-2, but Sly and Robertson name multiple football players as customers, including Green Bay Packers linebacker Mike Neal. Neal, Sly says, connected him with multiple teammates, including defensive end Julius Peppers. Pittsburgh Steelers linebacker James Harrison is another NFL player he has supplied, Sly says.

Clay Matthews is also named in the documentary for being provided with Percocet and asking for Toradol, a pain killer not legal in many countries.

Sly also says that he provided Clay Matthews, Green Bay’s Pro Bowl linebacker, with the prescription painkiller Percocet to help him deal with pain before at least one game. He also brags in one undercover video that Matthews texted him in an attempt to obtain Toradol, a powerful painkiller that is banned in many countries but not in the United States.