NBC News anchor Brian Williams’ reporting from New Orleans during Hurricane Katrina and his recounting of it afterward are part of an internal investigation that the news network has launched in the wake of a troubling on-air apology this week, according to a network source familiar with the probe.

Williams’ Katrina coverage — in particular his claim of seeing a dead body float by his French Quarter hotel room — has come under new scrutiny in the wake of his recent admission that he lied in claiming last week that he’d ridden in a helicopter in Iraq that was downed by a rocket-propelled grenade.

While doubters have noted correctly that the Quarter, New Orleans’ original high ground, remained largely if not completely dry, photographs and news reports from the time indicate there was flooding around the Ritz-Carlton, where the network source confirmed Williams stayed.

The hotel is located on Canal Street between Burgundy and Dauphine streets — technically just outside the Quarter, which is bounded by Esplanade Avenue, the Mississippi River, and Iberville and North Rampart streets. But most residents consider the downriver side of Canal Street, where the hotel is located, part of the Quarter.

Pictures shot at the time by a guest at the hotel show there was water outside the Ritz. It’s unclear how deep the water was: It’s shallow enough that the sidewalk below is clearly visible, but also deep enough that a boat is bobbing in the water. It is also unclear what day the pictures were taken.

A Times-Picayune account from Sept. 1, 2005, cites a hotel manager describing the Ritz as being surrounded by water and discussing the Ritz-Carlton’s efforts to evacuate guests. A subsequent report on Sept. 8 by the same reporter, Rebecca Mowbray, says the Ritz sustained significant flood damage and was shuttered. It would remain closed for at least 15 months during a renovation that cost more than $100 million, according to news accounts.

Tulane University professor Rich Campanella, who has published several books on the city’s geography and topography, took photographs outside the Ritz on the day after the storm that show shallow water in the street, and the sidewalks free of water. He noted that the water rose through the next day, Wednesday.

That corner of the Quarter is the neighborhood’s lowest part, he said, and while the flooding might be described as “trivial,” there was definitely water in the street around the Ritz-Carlton. Campanella himself remembers seeing a photo of a body floating not far away, in deeper water on North Claiborne Avenue near the Circle Food store.

“While it’s generally accurate to say the French Quarter evaded flooding, it’s not entirely precise,” Campanella said. “It seems to me there are strands of credibility here. It might also represent a genuine conflation. Like all of us who have told our Katrina experiences over and over, there comes a point where you really do start to blur specific memories.

“The question comes down to the rather gruesome notion of: What does it take to float a corpse?”

Whether or not Williams indeed saw a body in floating in the water from his hotel room window is likely unverifiable, but waterlogged corpses were not an uncommon sight in the days after the hurricane. A number of bodies were recovered in that general area, according to Times-Picayune accounts from the time and a New York Times map tracking the location of the bodies.

In a Sept. 14, 2005, blog post, Williams recounted seeing “a body outside the Ritz Carlton hotel,” but does not specify when. In an interview a year later he described looking out of his hotel window and watching “a man float by face down,” among other horrors.

“I felt something get dislodged that changes the usual arms-length relationship between me and the stories I cover,” he said. “These are Americans, these are my brothers and sisters, and one of them was floating by.”

Stories vary on just how high the water reached outside the hotel, and the likelihood of a body bobbing past. Most maps that attempted to show the floodwaters’ reach show the area receiving between 0 and 2 feet of water.

Capt. James Scott, who during Katrina commanded the New Orleans Police Department’s 1st District, just outside the French Quarter, said his memories of the days after the storm are somewhat blurred, but he couldn’t specifically recall a body outside the Ritz-Carlton.

But Scott said Williams’ accounts appear to be “a fair assessment” of the conditions when the water in the city reached its height.

“There was a time when Canal Street had water on it. They had about 3 feet on Canal, but kind of the dividing line for a lot of it, once it went down, was Rampart Street.

“But for a period of time the water was everywhere except in the old Quarter and by the river.”

“They did have water, and they had bodies around there initially, from the drownings. So there was bodies. I had a body right at the 1st District station that was floating at St. Louis and Rampart. When the water was high, there was a body right there.”

Retired NOPD Capt. Harry Mendoza, though, said the water that began rising Tuesday after the levee breaches barely rose above the sidewalk on Canal Street in that area. Mendoza said he led a team that used front-end loaders to clear Canal Street of palm trees and wires the day after the storm hit.

“There weren’t any bodies out there. The only water they had in the Quarter at all was probably at Iberville and Burgundy,” a low area around the backside of the hotel, “but nothing you couldn’t drive through. Nothing anybody would have drowned in, unless you physically tried to drown.”

Mendoza wasn’t in the area on Wednesday, when the floodwaters crept higher, though just how much higher is unclear.

Richard Rhodes, a Seattle business executive who was attending the opening of a new amusement attraction that weekend, said the floodwater reached as high as 4 to 6 feet above the street around the hotel, where he was staying and remained through the storm. He thought about swimming out, he said, but decided against it due to the foul water.

Rhodes, 54, said he didn’t see Williams there. Nor, he said, did he see any bodies until he was flown out by a news helicopter on Wednesday afternoon.

While it’s possible their stays didn’t overlap — Williams had first hunkered down and reported from the Superdome — his report of the hotel being “overrun with gangs” was an exaggeration, from what Rhodes recalled.

Rhodes said the hotel had invited employees to ride out the storm and “it kind of got out of control.”

“There was a kind of criminal element that had gotten in, and somebody had worked there and they brought their family. They were leaving the doors open, and other people were trying to come,” Rhodes said. “Two off-duty police officers were running around keeping the peace. There were scary moments, but criminal gangs? That’s crazy.”

Williams also said he suffered from a case of dysentery from ingesting floodwater during his reporting. While that is also likely unverifiable, Rhodes said the stomach ailment was going around the hotel. And at least one hotel guest who was interviewed by CNN on Sept. 1 said there were cases of dysentery being treated at the hotel by a group of infectious-disease doctors who set up a makeshift clinic there after being stranded. The doctors at the hotel were in town for a conference, said the guest, who was not a doctor.

Several news agencies reported at the time that those doctors raided a nearby Walgreens — with the company’s permission — to acquire medical supplies for the impromptu clinic. Rhodes said they saw the doctors wade across Canal Street.

In a memo that NBC News President Deborah Turness sent to staffers Friday afternoon, she said Williams had apologized to the Nightly News team and a wider group of NBC news staffers Friday morning for the discredited Iraq helicopter claim, “and specifically expressed how sorry he is for the impact this has had on all of you and on this proud organization.”

“As you would expect, we have a team dedicated to gathering the facts to help us make sense of all that has transpired,” Turness wrote.

Staff writers Gordon Russell and Martha Carr contributed to this report.