Washington, Nov 16 (AFP) Facebook's chief operating officer Sheryl Sandberg on Friday pledged a "thorough" review of a political consulting firm's work for the social network giant after one target criticized the techniques used as "black ops."

Like founder Mark Zuckerberg, Sandberg has said she was unaware her firm was working with Definers Public Affairs, a Republican opposition research group, which according to some reports acted as a "fake news" machine to help Facebook deflect criticism over its handling of Russian misinformation.

And she hit back at suggestions the company deliberately engaged in spreading falsehoods.

"We absolutely did not pay anyone to create fake news -- that they have assured me was not happening," Sandberg told CBS This Morning.

"And again, we're doing a thorough look into what happened but they have assured me that we were not paying anyone to either write or promote anything that was false. And that's very important." Sandberg said on her Facebook page that she was unaware of the work of Definers.

Chief executive Mark Zuckerberg on Thursday also said he was in the dark about the public relations firm, which according to a New York Times investigation sought to link Facebook critics to liberal financier George Soros.

Soros is a frequent target of conservative activists, and some of his critics appear to subscribe to anti-Semitic conspiracy theories.

Sandberg said of the Definers: "We're no longer working with them but at the time, they were trying to show that some of the activity against us that appeared to be grassroots also had major organizations behind them.

She added: "I did not know we hired them or about the work they were doing, but I should have. I have great respect for George Soros -- and the anti-Semitic conspiracy theories against him are abhorrent." Soros is a founder of the Open Society Institute, whose president Patrick Gaspard stepped up criticism of Facebook in an interview Thursday.

"There are broad questions about the role that Facebook is playing in the integrity of our elections, our democracy," Gaspard told National Public Radio.

"And frankly now that we know that they ran this black ops operation, there are questions about why they're following the model of people like Vladimir Putin. This is profoundly dangerous and disturbing."

NBC News meanwhile reported that a former employee of Definers, who asked not to be identified, described a website operated by the consulting group as an "in-house fake news shop" that sought to push stories into mainstream media. (AFP) CPS

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