Facebook founder and CEO Mark Zuckerberg meets Founder and Executive Chairman of Alibaba Group Jack Ma (not pictured), at the China Development Forum in Beijing, China, March 19, 2016.

Snopes, a fact-checking organization, announced on Friday its decision to end its partnership with Facebook, which has been ramping its efforts to curb misinformation on its services since the 2016 U.S. election.

Facebook and Snopes had been working together since December 2016 to fact check content on the social network. The company in 2017 paid Snopes as much as $100,000 for the work, according to Snopes.

"At this time we are evaluating the ramifications and costs of providing third-party fact-checking services, and we want to determine with certainty that our efforts to aid any particular platform are a net positive for our online community, publication, and staff," Snopes said in a statement.

Snopes said it has not closed the door on working with the company again, but it encouraged Facebook CEO Mark Zuckerberg to meet "with fact-checkers as part of his recently announced series of public discussions" in 2019.

The partnership is ending weeks after a report by The Guardian, in which multiple former Snopes employees criticized Facebook's efforts to stop fake content on its services.

"They've essentially used us for crisis PR," one former employee told The Guardian.

"Misinformation is an ever-evolving problem that we're committed to fighting globally, and the work that third-party fact-checkers do to help review content on Facebook is a valued and important piece of this effort," Facebook said in a blog post in December. At the time, the company said it had 35 fact-checking partners around the world.

A Facebook spokesperson said in a statement to CNBC that the company still has 34 other organizations it works with to fact check news on the site.

"We value the work that Snopes has done, and respect their decision as an independent business," the spokesperson said. "Fighting misinformation takes a multi-pronged approach from across the industry. We are committed to fighting this through many tactics, and the work that third-party fact-checkers do is a valued and important piece of this effort. We have strong relationships with 34 fact-checking partners around the world who fact-check content in 16 languages, and we plan to expand the program this year by adding new partners and languages."

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