WASHINGTON—Director of National Intelligence Tulsi Gabbard and the White House continued a multiday barrage against Barack Obama, alleging the former president and senior officials in his administration manufactured a false conspiracy suggesting Russia interfered in the 2016 election to undermine President Trump’s victory.

One day after President Donald Trump accused former President Barack Obama of treason over the intelligence assessment that Russia interfered in the 2016 election and sought to help Trump, Director of National Intelligence Tulsi Gabbard declassified a highly sensitive congressional report she claimed was more evidence of a “treasonous conspiracy.

Gabbard’s comments come amid the declassification of a trove of documents from the U.S. intelligence community that claim the Obama administration politicized intelligence.