NBC News chairman Andy Lack defended his network’s handling of Ronan Farrow’s Harvey Weinstein reporting in a lengthy memo to staff on Labor Day.

The 10-page memo provided to Fox News, which came with a cover letter and table of contents, was sent out after a former NBC News producer who was working with Farrow on the Weinstein probe said they were ordered to kill the report on direction from "the very highest levels at NBC."

But Lack fought back against the allegation in his memo, labeling talk about the network’s handling of the report "an unusual situation for a news division."

"We spent eight months pursuing the story but at the end of that time, NBC News – like many others before us – still did not have a single victim or witness willing to go on the record. (Rose McGowan – the only woman Farrow interviewed who was willing to be identified – had refused to name Weinstein and then her lawyer sent a cease-and-desist letter.)," Lack wrote. "So we had nothing yet fit to broadcast. But Farrow did not agree with that standard. That’s where we parted ways – agreeing to his request to take his reporting to a print outlet that he said was ready to move forward immediately."

We spent eight months pursuing the story but at the end of that time, NBC News – like many others before us – still did not have a single victim or witness willing to go on the record. — NBC News Chairman Andy Lack

Farrow did not immediately respond to Lack's statements. Farrow's report ultimately was published in The New Yorker in the fall of 2017 and he won the Pulitzer Prize for his work earlier this year.

The memo detailed what NBC claimed was the timeline of Farrow’s reporting as well as the interactions between network executives and Weinstein.

The details represented a sharp contrast from the claims of other people who worked on the report, including the producer who said he planned to accompany Farrow to Los Angeles to interview a woman “with a credible allegation of rape.”

"I was told not to do the interview and ordered to stand down, thus effectively killing the story," Rich McHugh, who left the network's investigative unit last month, told Fox News in a statement. "That was unethical, and a massive breach of journalistic integrity.

"Is there anyone in the journalistic community who actually believes NBC didn’t breach its journalistic duty to continue reporting this story?" McHugh added. "Something else must have been going on.”

Following the memo's release McHugh slammed Lack on Twitter.

"I'm not clear how NBC's report can be considered objective and thorough given I was never interviewed for the report and only learned about it when asked for comment by reporters late last week," McHugh wrote.

But Lack said there were no ulterior motives to punting the story and that it simply was "not ready to air."

"We regret the deterioration of NBC’s relationship with Ronan, and genuinely wish we had found a path to move forward together," Lack wrote. "That is why, in August of 2017, when Farrow objected to his editors’ conclusion we convened an independent group of the most experienced investigative journalists in our organization to review his material with fresh eyes. We asked them – tell us what, if anything, we can broadcast. But their conclusion was unequivocal – this story is not ready for air. (Further, they found several elements in Farrow’s draft script which did not hold up to scrutiny – described in the accompanying document.) It was Farrow’s decision, in the midst of this process, to pursue the story elsewhere."

Lack also hit back against the recent Daily Beast report suggesting that NBC may have canned the story due to back channel communications between Weinstein and NBC News President Noah Oppenheim. Lack labeled the claim "baseless speculation."

According to the Daily Beast, it was Oppenheim who made the decision to nix Farrow's piece. The exec reportedly didn’t want to upset a Hollywood powerhouse such as Weinstein when he had ambitions of returning to the movie industry.

Farrow and McHugh reportedly pitched the story investigating Hollywood's notorious "casting couch" practices in January 2017. The story originally was meant to air around that year's Oscars, which wouldn't have been good for the Hollywood-friendly Oppenheim, the screenwriter of several films including "Jackie," "The Maze Runner," and the first installment of the "Divergent" series. Insiders told Fox News at the time that NBC executives may have been wary of ruining relationships in Hollywood, and brittle from years of bad publicity and tabloid covers about its own stars’ behavior and personal lives.

NBC fought back Monday against the speculation by detailing interactions between executives and Weinstein. "Oppenheim had never met or spoken to Harvey Weinstein prior to April 2017," the memo stated.

"The accompanying document recounts every interaction NBC News executives and editors had with Weinstein and his attorneys," Lack wrote. "It will surprise no one that they were dishonest in their dealings with us, often mischaracterizing our brief conversations. But in each instance, their calls were either completely ignored or met with a boilerplate commitment to allow them to comment if and when something was ready for broadcast. None of this was kept secret from Farrow. None of it was different from the calls we receive on every other difficult investigative story our unit regularly breaks. And none of it played any roles in our decision making."

Lack continued, "As we get back to work this week, we will continue to pursue the toughest stories, in the most challenging circumstances, involving the most powerful people."

The memo came amid speculation that Lack could be fired from his position and that Comcast executives may be searching for a replacement. ABC News President James Goldston has been eyed for the NBC job, according to the New York Post.

Fox News’ Brian Flood, Samuel Chamberlain and Sasha Savitsky contributed to this report.