US President Donald Trump has compared whistleblowers to spies in leaked audio in which he alludes to the death penalty to punish “treason”.
Mr Trump was speaking at an event in New York when he said he wanted to know “who gave the whistleblower the information” that was used as the basis of an official complaint that sparked an impeachment inquiry into his presidency.
The comments come as The New York Times revealed that the whistleblower in question is a CIA officer who was at one point detailed to work at the White House.
Citing three people familiar with his identity, The Times reported the man has since returned to the CIA. Little else is known about him.
The Los Angeles Times earlier said it obtained audio of Mr Trump’s whisleblower comments from a person at the New York event.
“I want to know who’s the person who gave the whistleblower the information because that’s close to a spy,” Mr Trump was quoted as saying.
“You know what we used to do in the old days when we were smart? Right? The spies and treason, we used to handle it a little differently than we do now,” the Los Angeles Times quoted him as saying in a thinly veiled reference to the death penalty.
Mr Trump’s comments also came as a US House of Representatives committee heard testimony from the acting director of national intelligence, Joseph Maguire, on the whistleblower complaint.
Mr Maguire said he believed the whistleblower had acted in good faith and that he has tried to handle a unique situation as best he could.
“I believe that this matter is unprecedented,” he said.
The identity of the whistleblower has not been disclosed and his, or her, safety was raised during Mr Maguire’s testimony.
“And of course, you will do anything you can to protect the whistleblower from any attempts to retaliate against him or her, correct?” Democratic Congressman Raja Krishnamoorthi asked.
The whistleblower’s complaint alleged Mr Trump attempted to solicit the Ukraine government’s help to investigate Democratic presidential hopeful Joe Biden, whose son worked in Ukraine.
The whistleblower also alleged the White House moved to “lock down” records of the phone conversation in the days following the call, placing them in a more secure “codeword-level system” used to protect information sensitive to national security.
“This set of actions underscored to me that White House officials understood the gravity of what had transpired in the call,” the whistleblower said.
“I am deeply concerned that the actions described below constitute ‘a serious or flagrant problem, abuse, or violation of law or executive order’ that ‘does not include differences of opinion concerning public policy matters’, consistent with the definition of an ‘urgent concern’.”
The whistleblower report has triggered a controversy and prompted House Speaker Nancy Pelosi, a Democrat, to launch a formal impeachment inquiry this week into the Republican president.
Mr Trump has angrily denounced the Democratic-led hearing as a “witch hunt”.
The announcement has helped prompt a $US13 million ($19 million) flood of campaign cash to bolster Mr Trump’s re-election effort.
In the 24 hours that followed Ms Pelosi’s announcement on Wednesday morning, the campaign raised $US5m ($7.4m) from online donors in all 50 states, campaign manager Brad Parscale said.
In addition to the online money, Mr Trump was expected to have raised $US5m ($7.4m) for his campaign and the Republican National Committee from a Wednesday night fundraiser, followed by an additional $US3m ($4.4m) from a Thursday morning breakfast, according to an RNC official.
“Huge groundswell of support leading to Trump landslide in 2020!” Parscale tweeted on Wednesday.