Five-time NFL Most Valuable Player Peyton Manning branded allegations in an upcoming Al-Jazeera documentary that an Indianapolis anti-aging clinic supplied him with human growth hormone as “complete garbage.”

– GALLERY: The NBA’s top-ten player salaries
– VOTE NOW: End of Year Awards 2015
– #360view: McGregor has leverage, UFC control

The allegations are included in an Al-Jazeera investigative report titled “The Dark Side”, which was posted online on Sunday and aired later in the day, shared in advance with The Huffington Post.

“The allegation that I would do something like that is complete garbage and totally made up,” Manning said in a statement on Saturday issued through the Denver Broncos to US media.

“It never happened. Never. I really can’t believe somebody would put something like this on the air. Whoever said this is making stuff up.”

Neither the NFL nor the Broncos commented on the allegations. According to The Huffington Post, in the report British hurdler Liam Collins went undercover to expose the use of performanceenhancing drugs in sports.

As part of his probe Collins met with Charles Sly, a former pharmacist at the anti-aging Guyer Clinic in Indianapolis, where Manning once played for the NFL’s Colts. Sly said he mailed HGH to Manning’s household in 2011, sending it to Manning’s wife, Ashley to avoid a link to the sports star.

However, in a follow up interview with Al-Jazeera, Sly recanted the allegation, saying they were “absolutely false and incorrect”. The NFL collective bargaining agreement ratified in 2011 banned the use of HGH. However, the league did not begin testing for the substance until 2014.

Manning missed the 2011 season because of multiple neck surgeries, and joined the Broncos as a free agent prior to the 2012 campaign. The 39-year-old is one of the icons of the NFL whose clean-cut image has made him the most marketable player of his generation, earning around $12 million a year from endorsements according to Forbes.

Manning hasn’t played since November 15, as he battles a torn plantar fascia in his left foot. The allegations linking Manning to possible use of a banned drug are the biggest bombshell in a report that according to The Huffington Post also implicates other NFL players as well as some Major League Baseball players.