Sen. Rand Paul, R-Ky., said Monday that President Obama’s former national security adviser Susan Rice should testify on new reports that she sought to “unmask” the names of President Trump's transition officials caught up in surveillance.

Paul, on Twitter, called the reports on Rice a "smoking gun." The Hill reported on his calls for her to testify.

Paul was referring to reports by Fox News, Bloomberg and others that Rice sought to disclose the Trump associate names. Those names were apparently sent to members of the National Security Council and the heads of the CIA and National Intelligence.

As Fox News reported Monday, the names were part of incidental electronic surveillance of candidate and President-elect Trump and people close to him, including family members, for up to a year before he took office. These were not targets in the eavesdropping.

“I don’t think we should discount how big a deal it was that Susan Rice was looking at these, and she needs to be asked: Did President Obama ask her to do this? Was this a directive from President Obama?” Paul reportedly said.

White House Press Secretary Sean Spicer, asked about the revelations at Monday’s briefing, declined to comment specifically on what role Rice may have played or officials’ motives.

“I’m not going to comment on this any further until [congressional] committees have come to a conclusion,” he said, while contrasting the media’s alleged “lack” of interest in these revelations with the intense coverage of suspected Trump-Russia links.

Rice did not respond to an email seeking comment from Bloomberg View on Monday. The report pointed out that Rice was asked on “PBS NewsHour” in March about the possibility of incidental intelligence gathering and she responded, “I know nothing about this.”

Politico reported that Rice’s requests were likely not illegal, but offer “some political ammunition for Trump.”

When names of Americans are incidentally collected, they are supposed to be masked, meaning the name or names are redacted from reports – whether it is international or domestic collection, unless it is an issue of national security, crime or if their security is threatened in any way. There are loopholes and ways to unmask through backchannels, but Americans are supposed to be protected from incidental collection. Sources told Fox News that in this case, they were not.

Fox News also is told that House Intelligence Committee Chairman Devin Nunes knew about unmasking and leaking back in January, well before President Trump’s tweet in March alleging wiretapping.

Paul reportedly called for stronger limits on “unmasking people in the political process.”

He said he is considering legislation on unmasking in response to the Rice reports.