DENVER (CBS4)– Private investigators working for Peyton Manning visited the source of a report that he and other star athletes had obtained performance-enhancing drugs before the documentary aired late last year, according to a report from The Washington Post on Thursday.

In December, Al Jazeera reported that an intern at an Indianapolis anti-aging clinic was secretly recorded suggesting that Manning’s wife received deliveries of human growth hormone in 2011. Manning, then with the Colts, was rehabbing from neck surgeries.

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The intern, Charles Sly, recanted his statements, which were recorded without his knowledge. He said they were fabricated in an attempt to impress a potential business partner. Manning angrily denounced the report, calling it “completely fabricated, complete trash, garbage,” and insisting he never took shortcuts in his return to football after missing 2011 with neck problems.

Manning and the Broncos are preparing for Super Bowl 50 against the Carolina Panthers on Sunday.

Manning’s lawyers launched the private probe shortly after Al Jazeera started contacting athletes who would be named in documentary in December.

They hired investigators to identify, locate and interrogate Sly and sent a lawyer to examine Peyton and Ashley’s medical records at the Guyer Institute of Molecular Medicine in Indianapolis, according to Ari Fleisher, the former White House press secretary and crisis management consultant Manning hired.

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Fleisher told the Post that Manning’s investigative team didn’t interfere with subsequent investigations nor did they remove any medical records or coerce Sly into recanting his statements.

Fleisher did confirm to the Post that the Indianapolis anti-aging clinic shipped medication to Manning’s wife. But, citing her right to privacy, he declined to say if it was human growth hormone.

HGH is banned by professional sports leagues and is only legal to prescribe in a few specific medical conditions.

The NFL is reviewing the allegations with the assistance of the U.S. Anti-Doping Agency, something Manning has said he welcomes.

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