Facebook COO Sheryl Sandberg (AP Photo/Jose Luis Magana)

Facebook chief operating officer Sheryl Sandberg admitted Wednesday that she had received information about the company’s work with Definers, the Republican-affiliated consultancy that conducted opposition research into Facebook’s critics.

Her comments, written in a blog post Wednesday evening, appeared to walk back her statements from last week in which she said she did “not know” Facebook had hired Definers.

In Wednesday’s blog post, Sandberg said she did not initially remember Definers when she read a New York Times story that detailed how Facebook had employed the firm. She subsequently asked her staff to look into the matter to “double-check whether anything had crossed my desk.”

“Some of their work was incorporated into materials presented to me and I received a small number of emails where Definers was referenced,” Sandberg wrote. She also said: "I want to be clear that I oversee our Comms team and take full responsibility for their work and the PR firms who work with us.”

The admission could embolden Facebook’s critics who have been saying the social network mismanaged its response to a series of crises it has faced over the last year involving Russian meddling and data privacy.

Much of Wednesday’s post was written by outgoing policy chief Elliot Schrage – Sandberg’s post was an addendum at the bottom of Schrage’s - who offered more details about the company’s work with Definers.

Schrage said that the firm was originally hired to compile news clips and provide information to reporters, but the scope of the firm’s work expanded in ways that he regretted. “I’m sorry I let you all down,” Schrage wrote. “I regret my own failure here.”

But Schrage, who is known to colleagues as a combative and loyal protector of his boss Sandberg, also defended the work of Definers, including the decision to investigate progressive financier George Soros and his potential connections to an organization that is critical of Facebook.

Schrage said Facebook asked Definers to investigate who was behind a new coalition of critics called “Freedom from Facebook.” The consultancy “learned that George Soros was funding several of the coalition members. They prepared documents and distributed these to the press to show that this was not simply a spontaneous grassroots movement.”

“I believe it would be irresponsible and unprofessional for us not to understand the backgrounds and potential conflicts of interest of our critics,” Schrage added.

The Open Society Foundations, a philanthropic organization founded by Soros, has strongly objected to what it described as Facebook’s “unsavory tactics.” It has accused the company of mimicking right-wing efforts to demonize the Jewish Soros, who is a frequent target of anti-Semitic vitriol from the far right. Open Society did not immediately respond to a request for comment.

A Freedom from Facebook spokesman Eddie Vale said Wednesday: “We have said publicly, and Open Society has said publicly, they provide no funding yet Facebook continues to lie."

Sandberg, in her post on Wednesday, wrote: “It was never anyone’s intention to play into an anti-Semitic narrative against Mr. Soros or anyone else. Being Jewish is a core part of who I am and our company stands firmly against hate. The idea that our work has been interpreted as anti-Semitic is abhorrent to me — and deeply personal.”

Despite these controversies, Sandberg’s position at the firm is not in question, said Facebook chief executive Mark Zuckerberg in an interview that aired on CNN Tuesday night. Zuckerberg acknowledged missteps but said he would not step down as chairman of Facebook’s board, nor would he dismiss Sandberg.

“She has been an important partner for me for 10 years,” Zuckerberg said in the interview. “I am really proud of the work we have done together and hope we work together for decades more to come.” Facebook did not respond to a request for additional comment.

“It’s important for Facebook to recognize that this isn’t a public relations problem — it’s a fundamental challenge for the platform and their business model,” Sen. Mark R. Warner (Va.), the ranking Democrat on the Senate Intelligence Committee, told The Washington Post this week. ”I think it took them too long to realize that."

Facebook shares rose nearly 2 percent Wednesday as many tech stocks recovered from days of heavy losses.