NBC News is starting an internal investigation into the actions of Brian Williams, the embattled “Nightly News” anchor who has acknowledged misleading the public with his accounts of a harrowing helicopter episode in 2003.
The inquiry, confirmed on Friday by a person in the network’s news division, will be led by Richard Esposito, the head of NBC’s investigative unit.
In a staff memo on Friday, Deborah Turness, the president of NBC News, said that the network had “a team dedicated to gathering the facts to help us make sense of all that has transpired.”
Ms. Turness said that she and Mr. Williams had spoken with the “Nightly News” team on Thursday and addressed more employees in an editorial meeting on Friday.
“Brian apologized once again, and specifically expressed how sorry he is for the impact this has had on all of you and on this proud organization,” Ms. Turness said in the memo.
On Wednesday Mr. Williams admitted on his newscast that he had inaccurately claimed that he was in a United States military helicopter that was forced down after being hit by enemy fire in Iraq. He said he had been on a different helicopter, behind the one that was hit. He said he had “conflated’’ the two versions, and apologized.
It’s not clear if other people at NBC were aware that Mr. Williams’s version of the events was inaccurate.
Some military veterans and commentators have called for his resignation, claiming that the incident damaged not only the credibility of Mr. Williams but also the broader NBC News operation.
News of the internal investigation was first reported by The Daily News of New York.
Mr. Williams has not publicly addressed the issue since his Wednesday broadcast. His news broadcast on Thursday continued as planned, with segments on subjects like the measles outbreak, the hacking attack on Anthem insurance and the New York commuter train crash.
By Friday, the issue had drawn a frenzy of online criticism, with other statements by Mr. Williams drawing close scrutiny. Some blogs and media outlets questioned Mr. Williams’s description of what he saw while reporting on Hurricane Katrina, during which he described seeing a body floating down the street from his hotel window in the French Quarter. At the time, some news organizations had reported that the French Quarter was not flooded.
Inside NBC, executives canceled meetings and said that the issue was absorbing all of their focus.