Newly uncovered documents obtained through an FBI whistleblower confirm that federal agents under the Biden administration secretly accessed the phone records of multiple Republican senators as part of a covert investigation labeled “Arctic Frost.” The revelations, disclosed by Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa), have sparked outrage over alleged constitutional violations.

The documents, released publicly on Monday, indicate that the FBI conducted “preliminary toll analysis” on limited phone records belonging to eight sitting senators and one member of the House of Representatives. The investigation, tied to allegations of 2020 election interference, has drawn comparisons to Watergate by Grassley, who called the actions “disturbing and outrageous political conduct.”

Grassley emphasized that the FBI’s surveillance constituted an unconstitutional breach of privacy, urging accountability from federal officials. He noted that senators targeted had no knowledge of why they were under scrutiny, with Senate colleague Ron Johnson highlighting the urgency for more whistleblowers to come forward. The case file, labeled “ARCTIC FROST—Election Law Matters—SENSITIVE INVESTIGATIVE MATTER—CAST,” was uncovered after an FBI employee attempted to recertify for the bureau’s cellular analysis system.

The disclosures have intensified calls for transparency, with critics condemning the Biden administration’s handling of law enforcement operations.