WASHINGTON (AP) — A senior Federal Trade Commission official is criticizing Facebook's move to shut down the personal accounts of two academic researchers and terminate their probe into misinformation spread through political ads on the social network.

Facebook wrongly used a 2019 data-privacy settlement with the FTC to justify shutting down the New York University researchers' accounts this week, Samuel Levine, acting director of the FTC's consumer protection bureau, said in a letter Thursday to Facebook CEO Mark Zuckerberg,

Levine also said Facebook failed to honor a prior commitment to notify the FTC in advance of taking such an action.

Facebook maintained that the researchers violated its terms of service and were involved in unauthorized data collection from its massive network. The academics, however, say the company is attempting to exert control on research that paints it in a negative light.

The NYU researchers with the Ad Observatory Project had for several years been looking into Facebook's Ad Library, where searches can be done on advertisements running across Facebook's products.

The access was used to "uncover systemic flaws in the Facebook Ad Library, to identify misinformation in political ads, including many sowing distrust in our election system, and to study Facebook's apparent amplification of partisan misinformation," Laura Edelson, the lead researcher behind NYU Cybersecurity for Democracy, said Wednesday.

Facebook agreed in a 2019 consent decree settlement with the FTC to pay a record $5 billion for alleged violations of the privacy of users' personal data.

But Levine said in his letter that the consent decree allows Facebook to create exceptions to data collection restrictions "for good-faith research in the public interest."

"While it is not our role to resolve individual disputes between Facebook and third parties, we hope that the company is not invoking privacy — much less the FTC consent order — as a pretext to advance other aims," the letter says.

Facebook's action against the NYU project also cut off other researchers and journalists who got access to Facebook data through the project, according to Edelson, the NYU lead researcher.

The researchers offered Facebook users a web browser plug-in tool that let them volunteer their data showing how the social network targets political ads.

But Facebook said the browser extension was programmed to evade its detection systems and vacuum up user data, creating privacy concerns.

In a blog post late Tuesday, Facebook said it takes "unauthorized data scraping seriously, and when we find instances of scraping we investigate and take action to protect our platform."

Facebook representatives didn't immediately respond to a request for comment Thursday on Levine's letter.

Levine wrote that after Facebook wrongly asserting its actions against the researchers were required under the consent decree, it later acknowledged that was inaccurate. "While I appreciate that Facebook has now corrected the record, I am disappointed by how your company has conducted itself in this matter," he told Zuckerberg.

Facebook says it makes information on political ads available through its Ad Library and provides "privacy-protected data sets" to researchers through other means.

Facebook didn't admit wrongdoing in the 2019 settlement.

The FTC opened an investigation into Facebook in 2018 after revelations that data mining firm Cambridge Analytica had gathered details on as many as 87 million Facebook users without their permission.

In addition to privacy concerns, the FTC and Facebook have been wrangling over antitrust issues. The agency and 48 states and districts sued Facebook in December, accusing the tech giant of abusing its market power in social networking to crush smaller competitors. They were seeking remedies that could include a forced spinoff of the social network's Instagram and WhatsApp messaging services.

A federal judge recently dismissed the antitrust lawsuits, saying they didn't provide enough evidence to prove that Facebook is a monopoly. The ruling dismissed the FTC's complaint but not the case, giving the agency a chance to file a revised complaint.