SAN FRANCISCO — As many as 126 million people — or one-third the U.S. population — may have seen material posted by a Russian troll farm under fake Facebook identities between 2015 and 2017, according to testimony presented by Facebook's general counsel at a hearing before the Senate on Tuesday.

The figure is the largest yet of the possible reach Russian operatives had on the giant social platformin the run-up to last year's presidential election and afterwards and reflects Facebook's new disclosures that a Kremlin-linked misinformation agency used original content in users' feeds, as well as paid ads. Previously Facebook said 10 million people saw Russia-linked advertising that sought to sway U.S. voters.

More:Facebook: 10 million people saw Russia-backed election ads

The figures come as Capitol Hill readies itself for two more hearings on the ways Russia used social media to influence the U.S. 2016 election, scheduled to take place on Wednesday.