(CNN) -- CBS correspondent Lara Logan apologized Friday and said the network was "wrong" for a "60 Minutes" report that raised questions about the Obama administration's response to last year's attack on the U.S. diplomatic compound in Benghazi, Libya. The assault left four Americans dead, including Ambassador Christopher Stevens.
"In this case, we were wrong. We made a mistake," she said on "CBS This Morning." "That's disappointing for any journalist. It's very disappointing for me."
A primary source for the "60 Minutes" report on October 27 was a security contractor using the pseudonym "Morgan Jones," later identified as Dylan Davies. Davies told CBS he was able to reach the Benghazi compound on the night of September 11, 2012, scale a wall and even fight off a militant.
That story cast doubt on whether the Obama administration sent all possible help to try to save Stevens and his three colleagues. The "60 Minutes" story was cited by congressional Republicans who have demanded to know why a military rescue was not attempted.
Logan responded Friday to questions from CBS' Norah O'Donnell, who pressed her for details about Davies.
"What we know now is, he told the FBI a different story to what he told us," Logan said. "That was the moment for us when we realized that we no longer had confidence in our source and we were wrong to put him on air, and we apologize to our viewers."
Logan was also asked about how CBS vetted Davies and his story.
"We verified him, confirmed who he was, that he was working for the State Department at the time, that he was in Benghazi at the special mission compound the night of the attack," Logan said. "He showed us -- he gave us access to communications he had with U.S. government officials."
In a new book, "Jones" told the same story he told CBS. He also said he acted in violation of his employer's orders to stay away from the compound.
Logan said CBS has tried to contact Davies but has not heard from him.
The apology comes a day after CBS issued a statement saying, "60 Minutes has learned of new information that undercuts the account told to us by Morgan Jones of his actions on the night of the attack on the Benghazi compound. We are currently looking into this serious matter to determine if he misled us, and if so, we will make a correction."
A U.S. official told CNN Thursday that there were discrepancies between the contractor's accounts to the FBI and CBS, although the official did not specify them.
The New York Times, citing two senior government officials, reported Thursday that the contractor told the FBI he did not go the Benghazi compound on the night of the attack.
Incident report raised questions
The CBS story first came into question because of an incident report filed by the contractor's employer, the Blue Mountain security company. The incident report, obtained by CNN and first reported in The Washington Post, said the contractor never reached the Benghazi compound.
The incident report also revealed the real name of "Morgan Jones" to be Dylan Davies.
CBS initially stood by the story after the incident report came to light. Davies said he never saw the incident report. But he said it matched a false account he gave his Blue Mountain supervisor to cover up that he had disobeyed the supervisor's order not to go to the compound.
In a statement to CNN this week, Davies said, "The account in my book is consistent with what I gave to the FBI and U.S. authorities about what happened in Benghazi."
When Logan was asked Friday why CBS was willing to stand by its report after Davies lied to his employer, she said, "because he was very upfront about it; that was part of his story."
Hearing set for next week
CIA employees are scheduled to testify about the attack at a closed-door congressional hearing next week.
U.S. officials have said Stevens and information officer Sean Smith took refuge behind a heavy metal door at 10:30 p.m. on the night of the attack, about 30 minutes after attackers had breached the walls of the compound. The two were quickly overcome by smoke when attackers set fire to the building.
Also at 10:30 p.m., six security agents left a CIA annex a mile away. The six agents and 16 Libyan security officials regained control of the compound.
With the help of a rescue team that arrived from Tripoli at 1:15 a.m., the agents rescued about 30 Americans and took them to the CIA annex. They also took Stephens and Smith, although their condition at that time has not been made clear.
At 4 a.m., militants attacked the CIA annex. Navy SEALs Glen Doherty and Tyrone Woods were killed.