Sky News Australia has launched legal action against fact-checkers linked to Facebook.

The news organisation alleges the RMIT FactLab wrongly claimed some of its news reports were false.

It is demanding the fact-checkers retract their claims and pay compensation.

Earlier this year, Rebel News reporter Avi Yemini launched a defamation case against RMIT FactLab over a false fact-check on one of his reports, with documents uncovered in the case bringing to light the secret agreement between Meta and the university's FactLab.

Lawyers representing Sky News Australia have nominated at least five fact-checks published by RMIT FactLab since December that claimed Sky News content was false.

Four of the five articles were about the Indigenous Voice to Parliament referendum.

The FactLab released the five fact-checks despite the fact that their own International Fact-Checking Network (IFCN) certification had expired.

RMIT FactLab is required to have valid certification in order to post its verdicts about news items on Facebook.

The FactLab’s assessments can lead to news articles being blocked on social media, restricting both the public’s access to news and the news organisation’s ability to access revenue.

Sky News alleges that FactLab was “clearly misleading” the public by continuing to publish its verdicts and provide them to Facebook when it did not have the relevant certification required to do so.

Meta, which owns Facebook and Instagram, has suspended their partnership with RMIT due to its lack of certification.