Charlie Sly recanted allegations shortly after being visited by investigators hired by Peyton Manning's lawyers. Now, even his family doesn't know Sly's whereabouts as Al Jazeera pushes for more information from the Manning investigation firm.

Where in the world is Charlie Sly, the pharmacist who made a splash naming big-name athletes who allegedly took performance-enhancing drugs for Al Jazeera America's The Dark Side: Secrets of the Sports Dopers before suddenly recanting his story upon a visit from investigators hired by football legend Peyton Manning? On Friday, attorneys for the network told a judge that they had undertaken extensive efforts to locate him without success.

Al Jazeera America, which shuttered weeks after airing the documentary, continues to face a big defamation lawsuit from baseball superstars Ryan Zimmerman and Ryan Howard. In the past few weeks, with discovery in the case about to close, there's been some extraordinary emergency motions made in New York, Florida, Virginia and the District of Columbia.

For example, former MLB MVP Howard is now looking to quash a subpoena served on Verizon, his cellular provider, seeking six years of phone records. Meanwhile, Howard and Zimmerman are demanding a deposition for Dr. Mostefa Souag, the director general of Al Jazeera Media Network. They've told a judge he's personally responsible for the decision to broadcast the documentary and that he has knowledge of the reasons why Al Jazeera America was shuttered in the aftermath of the documentary. Lawyers for the suing athletes say that while they are willing to travel to Qatar to interrogate him, he's scheduled to be in Washington, D.C., next week for a luncheon at the National Press Club.

There's much more activity in the case including a noteworthy opinion on Wednesday regarding the undercover reporter with a confidentiality and non-disclosure agreement with Al Jazeera, but perhaps the biggest mystery is the one surrounding the disappearance of Sly.

Sly cooperated in the filming of the documentary, but on Dec. 24, 2015, he delivered a video statement to the network that stated that everything he said in 27 hours of prior recordings was false. The fact that Al Jazeera went ahead with broadcasting the documentary despite Sly's recantation is a major facet of Zimmerman's defamation lawsuit. According to the plaintiffs, it shows that Al Jazeera had sufficient knowledge of falsity amounting to actual malice when accusing the baseball players of doping.

Al Jazeera is primed to argue in response that Peyton Manning was a second source corroborating doping claims. (Manning's lawyer firmly denies he was a source.) If this case gets to trial, Al Jazeera will also tell a jury that it did not find Sly's denial to be credible.

Among the reasons why Al Jazeera is dubious about the video recantation is because Sly was under "duress," states court papers.

Shortly before Sly recanted, investigators hired by Manning's lawyers showed up at Sly's family home. Sly's sister called 911. Al Jazeera says that on the video, "Sly appeared to be reading a statement that was prepared for him while sweating profusely."

Now, Al Jazeera provides new details in a court filing on Friday.

The network subpoenaed AT&T, the cellular provider for Sly, and got over 21,000 pages of information related to calls and text messages to and from Sly's phone in a three-year period.

Among the information said to have been produced are five contacts between Sly and the chief executive of Phenix, Manning's investigation firm, as well as 117 contacts between Sly and a number registered to a senior investigator at Phenix between Dec. 17, 2015 and Jan. 9, 2016. There was also 96 text messages between the Sly and a Phenix investigator in the days after the video recantation.

Al Jazeera is pointing to these communications in an ongoing bid to compel discovery from Phenix.

If the defendant could possibly learn of the contents of the communications directly from Sly, well, that's why his disappearing act is being addressed in court.

According to a declaration filed on Friday by Rachel Stevens, of counsel at DLA Piper, Al Jazeera attempted to locate him at two addresses in Austin, Texas, associated with Sly in public record searches. A process server spoke with building personnel, none of whom recognized Sly.

So Al Jazeera contacted Sly's parents and looked for him at the family home. No dice.

Al Jazeera then reached out to two attorneys who had previously represented Sly. Neither knew his current whereabouts.

Subsequently, there was a deposition given by Taylor Teagarden, a former MLB player who was filmed in Sly's apartment as part of the documentary, as well as a deposition given by Sly's sister (the same one who called 911). Neither knew where to find Sly.

Al Jazeera reviewed the undercover footage again and identified license plates for cars driven by Sly. The attorneys looked at voter registration records. They used geolocation coordinates provided through the AT&T records. Zip. Nada. Zilch.

Given that he's seemingly a critical witness in this dispute, his absence will surely impact the litigation. Al Jazeera still hadn't been able to depose him and he'd surely be a pertinent trial witness. But the ramifications of his disappearance haven't yet been fully fleshed out in court. In the meantime, the vanishing of someone who once pointed fingers at some of the most famous athletes on Earth provides a riddling development.