Sen. Richard Blumenthal (D-Conn.) on Friday said that charges brought against a former Senate Intelligence Committee staffer were "extraordinarily serious and troubling."
Blumenthal's comments came a day after the staffer, James Wolfe, 57, was arrested and charged with repeatedly lying to the FBI about his contacts with three journalists and whether he gave them sensitive information.
"These charges against James Wolfe … are extraordinarily serious and troubling," Blumenthal said on CNN. "They involve leaks of classified information, potentially involving the Russia probe, to reporters."
The New York Times first reported Wolfe's arrest on Thursday.
The case against Wolfe also marked the first known instance of the Justice Department seizing a journalist's phone and email records under the Trump administration. The reporter, Ali Watkins, who works for the Times, was notified of the seizure in a letter on Thursday.
Blumenthal acknowledged on Friday that seizing reporters' records "is an intrusion" by the government, but said that doing so can sometimes be necessary to protect classified information.
"But very clearly, seizure of reporters’ records has to be an ultimate last resort," Blumenthal said. "Other means of obtaining the information have to be explored first under these procedures."