Getty Images

As Peyton Manning fights back against the Al Jazeera documentary that suggested he used human growth hormone in violation of NFL rules, private investigators are on the case.

The Washington Post reports that two men hired by Manning’s lawyers visited the parents of the documentary’s main source, Charlie Sly, before the documentary aired. Those two men were looking for Sly in an attempt to discredit the documentary. Sly’s parents were concerned enough that they called 911 and reported the two men.

Sly has since renounced everything he said in the documentary, which filmed him without his knowledge. Sly now claims he was just trying to make himself sound important when he claimed to have information about Manning and other athletes receiving performance-enhancing drugs.

Manning has denied ever using HGH and has declined to discuss whether his wife used the substance.