A Fox reporter investigating the "unmasking" of Trump transition officials by former national security adviser Susan Rice told "The O'Reilly Factor" Tuesday that they were examining whether Rice was told to request records about the president's associates.

FoxNews.com investigative reporter Malia Zimmerman told host Bill O'Reilly that she and Adam Housely were investigating whether "somebody from the [National Security Agency], for example, would have told [Rice] to ask for those reports, to ask for those names to be unmasked.

"That is what we’ve heard from some of our sources and so we’re looking into that angle as a possibility," she said.

Zimmerman and Housely reported Monday that 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.

"It’s just so vast, because we don’t know so many things," Zimmerman told O'Reilly. "We don’t know why they were surveilled – why they came up in the surveillance as incidental communications ... And we have to think about this in terms of this was going on for at least a year, according to our sources, possibly longer."

As national security adviser, Rice had the authority to request unmasking of names, a request which would have gone through the NSA.

The unmasked names were sent to the National Security Council, the Defense Department, then-Director of National Intelligence James Clapper and then-CIA Director John Brennan. It was not immediately known whether those people received it on a "need to know basis."

Late Tuesday, a former senior intelligence official told Fox News' Catherine Herridge that the finished intelligence products Rice was given about the Trump team included transcripts, which should never have been included.

The former official said Rice would have understood that an extensive paper trail would be generated and show who requested the unmasking, on what basis, and whether it was granted. This raises more questions about the motivation for Rice's request, her motivation and whether it was authorized higher-up in the Obama administration.

When O'Reilly asked Zimmerman if she believed the unmasking broke any laws, the reporter answered, "It’s pretty clear they were broken because the names were released to the media. So I believe that’s the case, but whether or not it was Susan Rice or someone else, we have no evidence to show who that person was that leaked."

However, Zimmerman added, "There’s a lot more to it, and we believe there’s more people involved."

Fox News' Catherine Herridge contributed to this report.