In this Jan. 7, 2015, file photo, Denver Broncos quarterback Peyton Manning considers a question after practice. (David Zalubowski/AP)

Five days before a documentary alleged that quarterback Peyton Manning and other star athletes had used performance-enhancing drugs, two men hired by Manning’s lawyers visited the parents of the documentary’s key witness. Both men wore black overcoats and jeans and, according to a 911 call from the house that evening, one initially said he was a law enforcement officer but didn’t have a badge.

After they told their daughter to call 911 the night of Dec. 22, Randall and Judith Sly stepped outside to talk to the strangers, who clarified they were private investigators, not cops. They had come to this red brick house with a well-manicured lawn looking for the Slys’ 31-year-old son, Charlie, a pharmacist who was the primary source in the upcoming documentary.

The revelation of the visit to the Slys’ home in this rural, upper middle class suburb is another in what has been a series of strange twists and turns since the Al Jazeera documentary, “The Dark Side: The Secret World of Sports Doping,” first aired. In the documentary, Sly boasted about helping pro football and baseball players cheat. In one scene, Sly implied that Manning took human growth hormone prescribed by an Indianapolis anti-aging clinic and shipped to Manning’s wife, Ashley.

Manning and most of the other athletes named in the report have denied taking banned substances. Sly has since recanted his accusations, which were recorded by Al Jazeera without his knowledge.

Sly’s claims have spurred investigations from the NFL and Major League Baseball that likely will take months. But the first investigation of Sly came before the documentary even aired, and was bankrolled by Manning, who will lead the Denver Broncos against the Carolina Panthers in Sunday’s Super Bowl.

Two men hired by Peyton Manning’s lawyers visited Charlie Sly's parents on Dec. 22. Sly was a pharmacist and the primary source in a documentary that alleged that quarterback Peyton Manning and other star athletes had used performance-enhancing drugs. (Hendricks County Communications Center)

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

Manning’s investigative team did nothing that would interfere with subsequent investigations, said Ari Fleischer, the former White House press secretary and crisis management consultant Manning has hired.

The lawyer who visited the Guyer Institute did not remove any records, Fleischer said, and Manning’s investigators in no way influenced or coerced Sly into issuing his recanting statement, which he recorded Dec. 24, the day after they had questioned him.

Sly’s lawyer, Travis Cohron, also said his client’s statement — which Sly issued without knowing exactly what he was recanting — was Sly’s idea. According to Cohron, everything Sly said in the documentary about helping pro athletes take performance-enhancing drugs was a fabrication to impress Al Jazeera’s undercover reporter, whom Sly claims he thought was a potential business partner.

“It was pure puffery,” Cohron said of his client’s words. “He was manufacturing a story to bolster his own appearance.”

The story Sly said he made up contained at least a bit of truth, though: The Guyer Institute did ship medication to Ashley Manning, Fleischer confirmed. Citing Ashley’s right to privacy, Fleischer declined to specify whether the medication was human growth hormone, which is banned by professional sports leagues and only legal to prescribe in America for a few specific conditions, such as growth hormone deficiency, HIV wasting syndrome and short bowel syndrome.

Here's what we know about the man who told Al Jazeera he gave performance enhancing drugs to Peyton Manning, Ryan Zimmerman, and other pro athletes. (Gillian Brockell/The Washington Post)

Manning’s pre-emptive investigation, Fleischer said, was a “natural reaction” to being asked to respond to anonymous allegations.

“When somebody accuses you of doing something you didn’t do — and Al Jazeera refused to tell us who it was — it’s only logical to say, ‘Who is it, and why are they doing this?’ ” Fleischer said. “That’s human nature.”

Search for the source

In the Al Jazeera documentary, Liam Collins, a former British hurdler, went undercover and claimed to pharmacists and doctors he was trying to revive his running career and was willing to cheat. With hidden cameras, Collins recorded Sly and asked him about procuring performance-enhancing drugs.

In speaking with Collins, Sly alleged illicit drug use by Washington Nationals third baseman Ryan Zimmerman and Philadelphia Phillies first baseman Ryan Howard, as well as by Pittsburgh Steelers linebacker James Harrison. Sly also said he helped numerous Green Bay Packers take banned substances, including linebackers Clay Matthews and Mike Neal, and defensive end Julius Peppers. (All of the players have denied the claims; Zimmerman and Howard have sued Al Jazeera for libel.)

On Dec. 4, Al Jazeera sent a wave of emails marked “urgent.” One arrived in the inbox of Tom Condon, Manning’s agent. Another went to Dr. Leonard “Dale” Guyer. Another went to Charlie Sly.

The personalized emails — which Al Jazeera said it sent to every person named in “The Dark Side” — detailed allegations against each person and requested comment. (Spokesmen for Manning and Sly described the emails to The Washington Post, but declined to share them. Al Jazeera’s lawyers also declined to provide the emails.)

Within days, Manning hired both the Gibson Dunn law firm and public relations consultant Fleischer to handle the situation. Fleischer said all parties agreed on a plan of attack: Identify the source and scrutinize the claims.

“Our thinking was it would be very helpful to find whoever it was who was making up lies about Peyton, and figure out why someone would fabricate information like this,” Fleischer said.

While Al Jazeera refused to identify its source, employees at the Guyer Institute noticed something familiar.

The unnamed source, Al Jazeera wrote in the email to Guyer, alleged that Peyton and Ashley Manning visited the anti-aging clinic after hours to “get IVs and shit .” The last two words reminded a few Guyer employees of a fleshy, fast-talking intern from a few years before.

“Guyer’s a small place,” Fleischer said. “They thought, ‘Well, of all the people who have been here, no one really talks like that but Charlie Sly.’ ”

Armed with a name, Manning’s investigators went looking for Sly, who had bounced around over the last few years, living alternately in Nevada, Texas and Indiana.

Sly was living in Austin and, according to his lawyer, completely unaware that professional athletes across the country — some of whom Sly now claims he has never met — were getting emails describing things Sly had said about them. Al Jazeera’s Dec. 4 email to Sly — which explained that Collins had lied and recorded all their conversations, and that all of this would soon be on television — ended up in Sly’s junk folder, according to his lawyer.

(In an email to the Post, Bob Corn-Revere, a lawyer for Al Jazeera, noted that, in addition to the Dec. 4 email, Al Jazeera sent Sly a registered letter Dec. 7 and left him a voicemail that he never returned.)

On Dec. 18 or 19, Sly got a phone call from Dustin Keller, the former New York Jets tight end Sly has known since they went to high school together in Indiana. Keller had gotten an email from Al Jazeera, requesting comment, and had deduced the source against him was Sly. (In the documentary, Sly says he helped Keller take banned substances throughout his college football career at Purdue University as well as in the NFL. Keller has not replied to multiple requests to comment.)

Even after that call, which Sly discussed with his family, Sly didn’t comprehend what was about to happen, his lawyer said. This was partly because the Slys were only vaguely familiar with Al Jazeera.

“The Sly family’s initial thoughts were, ‘This must be a scam,’ ” Cohron said. “His dad thought they [Al Jazeera] were only in the Middle East and they reported on terrorist attacks. The whole situation was surreal.”

The Slys, who refused multiple requests for an interview and referred all questions to their lawyer, started to realize this was not a scam when private investigators Brian Bauer and Ben Ford arrived at their home just before 5 p.m. on Dec. 22. Initially afraid, the Slys told their daughter Kaitlyn — Charlie’s younger sister, home from North Carolina for Christmas — to call 911. But by the time a police officer arrived a few minutes later, the investigators had allayed Randall and Judith’s fears.

The Slys told the officer the men could stay, dispatch notes show.

Charlie wasn’t home yet; he was due to fly in later. On Dec. 23, Bauer and Ford returned and — after the Slys put their lawyer on speakerphone — the investigators asked Charlie some questions.

As Bauer and Ford probed Sly’s background, asking about his connections to various athletes, Cohron couldn’t figure out who they worked for.

“They refused to say . . . other than a party interested in the Al Jazeera documentary,” Cohron said. He added: “It was a very cordial discussion.”

Sly told the investigators what his lawyer has said since the documentary aired: He made up everything regarding performance-enhancing drugs. Later, Sly and the lawyer Cohron decided they should come up with some kind of statement to rebut the upcoming documentary.

The next morning — Christmas Eve — Sly sat at the dining room table of his parents’ home. His father recorded the 55-second statement with an iPhone.

“My name is Charles Sly,” he began. “It has come to my attention that the broadcaster Al Jazeera has somehow obtained recordings or communications of me making statements concerning a number of athletes . . . There is no truth to any statement of mine that Al Jazeera plans to air.”

On Dec. 26, the Huffington Post — given an advance look at the documentary — published a story summarizing the allegations against Manning and other athletes. On Dec. 27, Manning angrily denied taking HGH, calling Sly a “slapstick” and the report a “freaking joke.” That night, the documentary aired.

“Since then, it’s pretty much been chaos,” Cohron said.

Only the beginning

While Sly has recanted everything he said about giving athletes banned drugs, several scenes in the documentary are more difficult to dismiss.

At one point, Sly offers Al Jazeera’s Collins a syringe he claims contains Delta-2, a banned steroid. Asked about that scene this week, Sly’s lawyer Cohron said his client lied and that the syringe actually contained a vitamin supplement.

In another scene, Taylor Teagarden, a journeyman catcher who played with the Chicago Cubs, is waiting outside Sly’s apartment. Once inside, Teagarden talks about taking Delta-2.

Teagarden did not reply to requests for comment. Cohron claims Teagarden was lying to help Sly appear to be a steroid dealer.

Cohron says his client doesn’t know why two Vancouver men — who both are recorded offering Collins banned substances — praised Sly as a doping “genius,” according to Al Jazeera.

“He’s the only guy I trust,” said pharmacist Chad Robertson, who is also recorded bragging about how easy it is to help athletes evade tests.

“He takes smart drugs to a whole new level,” said physician Brandon Spletzer, who is also recorded offering to destroy medical records if doping investigators ask for them.

Manning’s investigators are satisfied Sly’s claims about the star quarterback are false.

“It’s like Peyton said: It’s a bunch of hooey and garbage,” said Bauer, who last week spoke briefly with a reporter at the Greenwood, Ind., office of his company, Phenix Investigations.

Bauer referred most questions to Manning’s lawyers, but denied the claim that he introduced himself to the Slys as law enforcement.

“Impersonating a law enforcement officer is against the law, so obviously I didn’t do that,” said Bauer, a balding, bulky redhead who wore a skin-tight long-sleeved Under Armour shirt and jeans. “Otherwise I would have been arrested.”

Sly is cooperating with investigators from both Major League Baseball and the NFL, his lawyer said. Sly also could be called to testify in Zimmerman’s and Howard’s lawsuits against Al Jazeera.

The central role of the Guyer Institute in the documentary again has drawn attention to the controversial anti-aging industry, which some medical and law enforcement experts say is rife with physicians operating in legal and ethical gray areas involving substances such as human growth hormone.

Dr. Guyer declined an interview request this week. Stephen Cooke, an Indianapolis public relations executive who said he was working with Guyer, initially offered to answer questions, and then didn’t reply to multiple emails and voice messages. In multiple statements since the documentary aired, Peyton Manning has never denied that the Guyer clinic shipped human growth hormone to his wife, as Sly alleged. Manning has just denied ever taking it.

“We’ve never said he [Sly] had everything wrong. We just said what he said about Peyton was wrong,” Fleischer said. “It’s like the saying . . . Someone with a little bit of knowledge can be a dangerous thing.”