Facebook was allegedly aware of the problems it had with measuring the time spent viewing video ads more than a year before it reported the issues.

A complaint filed by a group of small advertisers, dubbed LLE One, in a California federal court in 2016 said the tech giant engaged in unfair business conduct in reporting of inaccurate metrics. Now, the group – made up of Crowd Siren, Social Media Models, and defunct startup Quirky – has added a fraud claim and accused Facebook of knowing about the video metric issues back in January 2015, as first reported by the Wall Street Journal. The complaint also alleges that the scale of miscalculation is far worse than it was previously understood to be.

The new filing comes on the back of a review of around 80,000 pages of internal Facebook records, obtained as part of the court proceedings, by the plaintiffs.

The proceedings stem from back in September 2016 when it was revealed that Facebook had been miscalculating the time spent watching videos by between 60 and 80 per cent. This miscalculation occurred as the average time users spent watching videos only factored in views of more than three seconds.

On the back of the revelation, Facebook began looking at its other metrics and found other miscalculations. This led to it changing the way metrics were handled and have its metrics audited by the Media Ratings Council.