
Back in January, the billionaire philanthropist labelled the tech companies a "menace" in a speech to the World Economic Forum, calling for increased government regulation.
But now, three internal sources claim that Sandberg requested information on Soros' financial investments.
A Facebook spokesperson confirmed to Buzzfeed that Sandberg had ordered research into the "motivations" behind Soros' speech and had asked that staff look into his trading of Facebook stock.
"Sheryl never directed research on Freedom from Facebook", the spokesperson added, referring to an anti-Facebook campaign. "Definers researched this using public information".
Definers "learned that George Soros was funding several of the coalition members", Elliot Schrage, Facebook's outgoing head of communications and policy, said in a statement last week. The company continued to state: "That research was already underway when Sheryl sent an email asking if Mr. Soros had shorted Facebook's stock".
Facebook wanted to deflect some of the mounting criticism it faced after both providing the vehicle for Russian agents to disrupt the US 2016 presidential election and leaking the personal data of millions of users to the Trump campaign consultancy Cambridge Analytica.
Sandberg had previously said that she didn't initially remember Definers when she read the story by the Times, which revealed Facebook hired the firm. Facebook also reportedly hired a Republican opposition research firm to discredit activist protesters critical of Facebook's data breaches.
Zuckerberg himself, meanwhile, said he hadn't heard of Definers before reading a report from the New York Times about his company's misstep.
More news: Box Office Report: Close to 100 cr in worldwide grossAmong the tech whiz kids, Sandberg as chief operating officer offered a steadier hand as a result of her background working for former US Treasury secretary Larry Summers and the philanthropic arm of Google.
But the revelations are likely to escalate pressure on Sandberg, an embattled Silicon Valley star and feminist author.
In that post, Sandberg did not explicitly deny that she had asked for research into Soros.
Schrage taking the hit for the controversy was seen by some as convenient, since he had said he was leaving the social network after working there for more than a decade.
Facebook hired Definers a year ago to monitor media coverage and then expanded its role to include campaign-style research and other public relations work. "Definers was hired, we have lots of firms". Kaplan is the company's vice president of global public policy.
"In light of Sandberg's continuously changing story on the Soros research, there's no way their denials about attacking other critics can be taken at face value", Vale told the New York Times.
"We were not satisfied with that answer", he said.