Al Jazeera says it had a second, "impeccably placed" source to back up the network's recent assertion that human growth hormone shipments were provided to Peyton Manning's wife.

The network's documentary "The Dark Side" attributed the charge to Charlie Sly, a former worker at the Guyer Institute of Molecular Medicine where Manning was treated.

On undercover tapes aired by Al Jazeera, Sly said "all the time we would be sending Ashley Manning drugs. Like growth hormone, all the time, everywhere, Florida. And it would never be under Peyton's name, it would always be under her name."

Sly subsequently recanted what he said on the tapes, calling his statements "absolutely false and incorrect."

But Al Jazeera reporter Deborah Davies is standing by the statements. In an interview on Sunday's "Reliable Sources," she said "we had a second source" that corroborated Sly's information.

Davies said she could not identify the anonymous source, but called the person "absolutely impeccably placed, knowledgeable, and credible," someone who gave Al Jazeera more confidence in what Sly said on tape.

She said the source confirmed that shipments of HGH, or human growth hormone, were "repeatedly sent to Ashley Manning in Florida and other places in the U.S."

Ashley Manning has not denied receiving shipments of HGH. But Peyton Manning has denied taking any of it.

He called the overall report "garbage" and told ESPN "any medical treatments that my wife received, that's her business. That has nothing to do with me."

Asked to comment on Davies' assertion about a second source, Ari Fleischer, who is representing the Mannings, said in an email, "It doesn't matter if Al Jazeera has one source or ten sources about Ashley. It's meaningless."

"Given the fact that Peyton publicly said he never took anything sent to Ashley, and Tom Condon, Peyton's agent, said any medication shipped to Ashley was by prescription and taken solely by her, what difference does it make about Ashley?" Fleischer said. "The only thing left to Al Jazeera's story is an attempt to violate Ashley Manning's medical privacy."

Fleischer added, "You notice Deborah Davies didn't say Peyton is already on record saying he didn't take his wife's medicine. Once she acknowledges that, there is no legitimate journalistic purpose in pursuing his wife."

Davies disagrees. Other players have been linked to HGH use in the past, she said. And in this case, "when Sly says an anti-aging clinic is shipping HGH to the wife of a player, that is part of a whole trail of evidence and it does raise questions."

Questions, but not answers. "I think it's kind of an incremental documentary that is trying to present itself as... a little bit more of a hammer blow," NPR media correspondent David Folkenflik said on "Reliable Sources."

Folkenflik said the documentary should have made mention of the second source and explained "how well-sourced" the person was.

So why didn't Al Jazeera do that?

"I suppose because it would simply have led to another range of speculation, another set of fishing expedition questions," Davies said. "The second source is credible, well-placed, knowledgeable, and cannot be named. And that's all that we can say for now."

She signaled that her reporting on the subject will continue, and she hopes others' reporting will, too.

"This is something that will hopefully kick off a bigger debate and raise all sorts of issues," she said.

Watch: "Reliable Sources" panel discussion about the Davies interview