Washington — President Trump has criticized both Democrats and the whistleblower who raised concerns he may have used his office for political gain. At a private event in New York on Thursday, the president compared the whistleblower and any White House employees cited in the complaint to "spies," and suggested they had committed treason.

In a detailed, nine-page complaint, the anonymous whistleblower also said "senior White House officials" worked to "lock down" all records of Mr. Trump's phone call, out of fear "they had witnessed the president abuse his office for personal gain." President Trump repeatedly urged Ukraine's new president to investigate Joe Biden and his son during the call, according to a summary of the discussion released this week.

The whistleblower said multiple White House officials were "deeply disturbed" and were "directed" by White House lawyers to remove a transcript of the call from the regular computer system and place it instead in a separate system normally reserved for classified, highly sensitive information.

CBS News correspondent Paula Reid says the president and his allies have sought to exploit any flaw in the whistleblower's account, repeatedly pointing out that the information contained in the complaint about Mr. Trump's call with Ukrainian President Volodymyr Zelensky was secondhand. Democrats have said the attacks could deter anyone else with information about the complaint from coming forward.

"What these guys are doing, Democrats are doing to this country, is a disgrace," fumed Mr. Trump on Thursday. He suggested the investigation into the whistleblower's accusations would backfire on Democrats in November 2020.

"They can't do any work. They're frozen," the president said. "The Democrats are going to lose the election. They know it."

Trump on "spies and treason"

Lawyers for the whistleblower said in a statement that their client fears "reprisal."

At the private event on Thursday in New York, President Trump blasted the whistleblower who filed the complaint as "highly partisan," and even alluded to capital punishment for those behind the complaint.

In video of his remarks posted by Bloomberg, Mr. Trump characterized the investigation into his actions as "war," and called the people behind the allegations "sick." The video appeared to have been captured on a cellphone.

"That person never saw the report, never saw the call," Mr. Trump said of the whistleblower. "He never saw the call - heard something and decided that he or she, or whoever the hell they saw - they're almost a spy."

"I want to know who's the person, who's the person who gave the whistleblower the information? Because that's close to a spy," the president told the U.S. diplomatic team. "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."

Treason is still punishable by death in the U.S., but the last time anyone was executed for it was in the 1860s. The last person convicted of treason in the U.S. was Japanese-American Tomoya Kawakita, who was sentenced to death in 1952 for tormenting American prisoners of war during World War II. His sentence was commuted to life imprisonment.

Giuliani's role

The controversy over the whistleblower complaint has also brought new scrutiny of the role of President Trump's personal attorney Rudy Guiliani. He is mentioned 30 times in the complaint, which cites meetings he had with at least seven Ukrainian officials.

Giuliani has admitted pressuring Ukraine to open an investigation into former Vice President and current Democratic presidential candidate Joe Biden, and his son Hunter. Giuliani has cited text messages as evidence that he did so at the direction of the State Department, and even suggested he "should get some kind of an award" for the meetings.

CBS News' Reid says Mr. Trump has long viewed Ukraine as a home to political enemies. In 2017 he tweeted about "Ukrainian efforts to sabotage" his campaign, musing, "where is the investigation?"

A Ukrainian prosecutor told the Washington Post on Thursday that, "from the perspective of Ukrainian legislation, (Hunter Biden) did not violate anything." Mr. Trump had cited that prosecutor's predecessor in remarks aimed at stirring up suspicions that the Bidens acted improperly.

That didn't stop President Trump from doubling down on his accusations against the Bidens, whom he claimed on Thursday were "walking away with millions of dollars from Ukraine."

The State Department, too, has now been implicated in the controversy. It has acknowledged that it did facilitate a meeting between Giuliani and Ukrainian officials, but Secretary of State Mike Pompeo insists officials acted appropriately.

The whistleblower's complaint raised concerns about White House efforts to restrict access to the records of the call. According to the complaint, White House officials were "directed" to remove the electronic transcript from the computer system to "a separate electronic system that is otherwise used to store and handle classified information of an especially sensitive nature."

CBS News national security analyst and former acting director of the CIA, Michael Morell, told "CBS This Morning" the system referred to in the complaint is reserved for "the government's most sensitive information."

"It is where CIA covert action information is kept. This summary of the conversation comes nowhere close to needing to be on that system," he said.

The White House has not yet explained why records of the call were allegedly moved to that system.