The Senate Intelligence Committee faced “specious” claims of executive privilege from the White House counsel’s office that impeded a years-long and bipartisan probe into Russian interference in the 2016 election, according to the committee’s final report in the investigation released Tuesday.

The committee, in a 966-page report that details extensive ties between Russian officials and individuals with the Trump campaign and transition team, said it frequently utilized subpoenas in compelling witness testimony and documents as part of the investigation.