Tulsi Gabbard, the director of national intelligence, has called for Barack Obama and former senior US national security officials to be prosecuted after accusing them of a “treasonous conspiracy” intended to show that Donald Trump’s 2016 presidential election win was due to Russian interference.

She said Obama and senior officials in his administration had “[laid] the groundwork for … a years-long coup” against Trump after his victory over Hillary Clinton by “manufacturing intelligence” to suggest that Russia had tried to influence the election. That included using a dossier prepared by a British intelligence analyst, Christopher Steele, that they knew to be unreliable, Gabbard claimed.

The post-election intelligence estimates contrasted with findings reached before the election, which indicated that Russia probably was not trying to interfere. In extraordinary comments calling for prosecutions, she added: “The information we are releasing today clearly shows there was a treasonous conspiracy in 2016 committed by officials at the highest level of our government.