The White House on Tuesday said an email that former national security adviser Susan Rice sent herself on President Donald Trump's Inauguration Day “raises a lot of serious questions.”

Sens. Chuck Grassley (R-Iowa) and Lindsey Graham (R-S.C) called on Rice this week to explain what they described as an “unusual” email she sent insisting that former President Barack Obama wanted to make sure the investigation into Russian meddling was done “by the book.”

White House principal deputy press secretary Raj Shah told “Fox & Friends” Tuesday that the email suggests the Obama administration “didn't operate by the book.”

“You write an email about doing something by the book, it's pretty clear you didn't operate by the book,” the White House spokesman said. “It raises a lot of serious questions.”

Shah added that the email represents a story connected to the ongoing Russia investigations but has been under-reported by the “mainstream media,” and that being the possibility that the Obama White House “prompted this investigation.”

“There are real questions that Sen. Grassley and Sen. Graham have raised. And I think they demand answers.”

Last week, Fox News and some Republicans claimed newly unearthed text messages showed President Barack Obama tampered with the federal investigation into Hillary Clinton's emails.

However, according to a report by The Wall Street Journal, the messages instead were related to the former president asking for information about the Russian investigation ahead of a meeting with Russian President Vladimir Putin, where he planned to confront the former KGB officer about meddling in the 2016 election.

Fox News ran with the story for the majority of the day, claiming the texts “are raising even more questions about what the FBI and former President Obama knew the Clinton investigation.”