A former CBS News reporter who quit the network over claims it kills stories that put President Obama in a bad light says she was spied on by a “government-related entity” that planted classified documents on her computer.

In her new memoir, Sharyl Attkisson says a source who arranged to have her laptop checked for spyware in 2013 was “shocked” and “flabbergasted” at what the analysis revealed.

“This is outrageous. Worse than anything Nixon ever did. I wouldn’t have believed something like this could happen in the United States of America,” Attkisson quotes the source saying.

She speculates that the motive was to lay the groundwork for possible charges against her or her sources.

Attkisson says the source, who’s “connected to government three-letter agencies,” told her the computer was hacked into by “a sophisticated entity that used commercial, nonattributable spyware that’s proprietary to a government agency: either the CIA, FBI, the Defense Intelligence Agency or the National Security Agency.”

The breach was accomplished through an “otherwise innocuous e-mail” that Attkisson says she got in February 2012, then twice “redone” and “refreshed” through a satellite hookup and a Wi-Fi connection at a Ritz-Carlton hotel.

The spyware included programs that Attkisson says monitored her every keystroke and gave the snoops access to all her e-mails and the passwords to her financial accounts.

“The intruders discovered my Skype account handle, stole the password, activated the audio, and made heavy use of it, presumably as a listening tool,” she wrote in “Stonewalled: My Fight for Truth Against the Forces of Obstruction, Intimidation, and Harassment in Obama’s Washington.”

This is outrageous. Worse than anything Nixon ever did.

Attkisson says her source — identified only as “Number One” — told her the spying was most likely not court-authorized because it went on far longer than most legal taps.

But the most shocking finding, she says, was the discovery of three classified documents that Number One told her were “buried deep in your operating system. In a place that, unless you’re a some kind of computer whiz specialist, you wouldn’t even know exists.”

“They probably planted them to be able to accuse you of having classified documents if they ever needed to do that at some point,” Number One added.

In her book, Attkisson says CBS lost interest in her coverage of the deadly attack on the US Embassy in Benghazi, Libya, and killed her stories of the federal “Fast and Furious” gun-running scandal.

Both CBS and the White House declined to comment.