The lawyer who founded Judicial Watch and later Freedom Watch, Larry Klayman, has sent a letter to Rep. Devin Nunes, R-Calif., chairman of the Permanent Select Committee on Intelligence, asking him to look at a whistleblower's evidence of "systematic illegal surveillance on prominent Americans, again including the chief justice of the Supreme Court, other justices, 156 judges, prominent businessmen such as Donald Trump, and even yours truly."

That spying was done, Klayman's letter contends, by the FBI.

It's become a major issue following President Trump's assertion that he and Trump Tower were spied upon by the federal government, and the subsequent denials by intelligence and law-enforcement officials, including FBI Director James Comey, who famously cleared Hillary Clinton on accusations she mishandled classified information as U.S. secretary of state.

Klayman has been working with Dennis Montgomery, a former NSA and Central Intelligence Agency contractor who "left the NSA and CIA with 47 hard drives and over 600 million pages of information, much of which is classified."

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Montgomery then "sought to come forward legally as a whistleblower to appropriate government entities, including congressional intelligence committees, to expose that the spy agencies were engaged for years in systematic illegal surveillance on prominent Americans."

Explained Klayman: "Working side by side with former Obama Director of National Intelligence James Clapper, who lied in congressional testimony, and former Obama Director of the CIA, the equally ethically challenged John Brennan, Montgomery witnessed 'up close and personal' this "Orwellian Big Brother' intrusion on privacy, likely for potential coercion, blackmail or other nefarious purposes."

Trust the government? Maybe you shouldn't. Read the details in "Lies the Government Told You," by Judge Andrew Napolitano.

But he said the testimony has been essentially ignored.

Now, however, with the issue pending before Congress, there even are media reports that appear to substantiate the general claims that the government has been spying. The New York Times in January referenced wiretapping at Trump Tower, and just this week ABC News documented that the FBI monitored Trump Tower.

The report claimed, "But it was not placed at the behest of Barack Obama, and the target was not the Trump campaign of 2016. For two years ending in 2013, the FBI had a court-approved warrant to eavesdrop on a sophisticated Russian organized crime money-laundering network that operated out of unit 63A in Trump Tower in New York."

It resulted in the indictments of more than 30 people, ABC said.

Explained the report: "The FBI investigation did not implicate Trump. But Trump Tower was under close watch. Some of the Russian mafia figures worked out of unit 63A in the iconic skyscraper – just three floors below Trump's penthouse residence – running what prosecutors called an 'international money-laundering, sports gambling and extortion ring.'"

Klayman, a Washington watchdog who repeatedly took on the Clinton political machine to investigate suspicion of wrongdoing, explained in his letter to Nunes, which was copied to other members of Congress, that he previously won a judgment from U.S. District Judge Richard Leon preliminarily halting the "illegal, warrantless, and massive surveillance of U.S. citiznes and lawful residents" in 2015.

As part of Nunes' hearing on claims of government spying, he invited "anyone who has information about these topics to come forward."

Klayman said that is exactly what Montgomery has done.

"There is a myriad of evidence, direct and circumstantial, of the illegal and unconstitutional surveillance disclosed to the FBI by Montgomery," said Klayman, describing how his client made an on-camera interview with the agency about the misdeeds some time ago.

He said Montgomery "holds much of the roadmap to 'draining the swamp' of this corruption of our democracy."

Montgomery, Klayman said, has information "that the spy agencies were engaged for years in systematic illegal surveillance on prominent Americans."

During Montgomery's interview with FBI General Counsel James Baker, under grants of immunity, he "laid out how persons like then businessman Donald Trump were illegally spied upon by Clapper, Brennan, and the spy agencies of the Obama administration."

"He even claimed that these spy agencies had manipulated voting in Florida during the 2008 presidential election, where illegal tampering resulted in helping Obama to win the White House."

But that interview, "conducted and videotaped by Special FBI Agents Walter Giardina and William Barnett, occurred almost two years ago, and nothing that I know of has happened since."

Klayman wrote that it appears to have been "buried" by Comey, possibly because "the FBI itself collaborates with the spy agencies to conduct illegal surveillance."

He said he previously visited with a staff lawyer, Allen Souza, to inform Nunes of questions that needed to be put to Comey while under oath.

"My expressed purpose: to have Chairman Nunes of the House Intelligence Committee ask Comey, under oath, why he and his FBI have seemingly not moved forward with the Montgomery investigation while, on the other hand, the FBI director recently claimed publicly, I believe falsely, that there is 'no evidence' of surveillance on President Trump and those around him by the Obama administration.

"Indeed, there is," he wrote.

He tells members of Congress that Comey needs to be grilled during a subsequent hearing, now set for March 28. He asks Nunes to respond by March 24 to let "the American people, and Mr. Montgomery … know where you and the other members of your committee stand."

"Do you intend to get at and investigate the full truth, or as has regrettably been the case for many years in government, sweep the truth under the carpet?"

Other recipients of the letter were Reps. Adam Schiff, Mike Conaway, Peter King, Frank LoBiondo, Tom Rooney, Ileana Ros-Lehtinen, Michael Turner, Brad Wenstrup, Chris Stewart, Rich Crawford, Trey Gowdy, Elise Stefanik, Will Hurd, Jim Hines, Terri Sewell, Andre Carson, Jackie Speier, Mike Quigley, Eric Swalwell, Joaquin Castro and Denny Heck.

Trust the government? Maybe you shouldn't. Read the details in "Lies the Government Told You," by Judge Andrew Napolitano.