U.S. Acting Director of National Intelligence Joseph Maguire (front) testifies before the House Intelligence Committee during a hearing titled "Whistleblower Disclosure" on Capitol Hill in Washington D.C., the United States, on Sept. 26, 2019. (Photo by Ting Shen/Xinhua)

WASHINGTON, Sept. 26 (Xinhua) -- A U.S. congressional panel on Thursday released a declassified version of a whistleblower complaint about President Donald Trump's interactions with his Ukrainian counterpart Volodymyr Zelensky.

In the whistleblower complaint, which was filed on Aug. 12 by an unidentified intelligence official and just released by the House Intelligence Committee, the official warned that Trump "is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election."

The official added that the interference includes "pressuring a foreign country to investigate one of the President's main domestic political rivals," without explicitly pointing out who that rival was, adding that Trump's personal lawyer, Rudi Giuliani, "is a central figure in this effort."

According to the rough transcript of a July 25 phone call between Trump and Zelensky released Wednesday by the White House, Trump mentioned Democratic presidential candidate Joe Biden several times during the call, at one time suggesting that the Ukrainian president cooperate with Giuliani and U.S. Attorney General William Barr in investigating into how Biden stopped a prosecution of a Ukrainian gas company which might be related to his son, Hunter Biden.

"I heard you had a prosecutor who was very good and he was shut down and that's really unfair," Trump told Zelensky, the transcript showed. Referring to Giuliani, Trump said: "I will ask him to call you along with the Attorney General ... If you could speak to him that would be great."

"There's a lot of talk about Biden's son, that Biden stopped the prosecution and a lot of people want to find out about that. So whatever you can do with the attorney general would be great," Trump said.

The whistleblower cited "White House officials who had direct knowledge of the call" as saying Trump pressured Zelensky "to initiate or continue an investigation into the activities of Former Vice President Joseph Biden and his son, Hunter Biden." The whistleblower used the full version of Biden senior's first name.

The whistleblower said White House officials had said they were "disturbed by what had transpired" in the Trump-Zelensky conversation, telling the whistleblower that they were "already in discussion" with White House lawyers about "how to treat the call because of the likelihood, in the officials' retelling, that they had witnessed the president abuse his office for personal gain."

The whistleblower "learned from multiple U.S. officials" in the days following the phone call that senior White House officials had engaged in blocking "all records of the phone call."

Senior White House officials, the whistleblower said, "had intervened to 'lock down' all records of the phone call, especially the official word-for-word transcript of the call that was produced -- as is customary -- by the White House Situation Room. This set of actions underscored to me that White House officials understood the gravity of what had transpired in the call."

According to the whistleblower complaint, Giuliani acted as a conduit between Trump and Ukrainian officials, relaying messages back and forth. His role, the whistleblower said, had raised concerns among U.S. officials, who had spoken with Giuliani "in an attempt to 'contain the damage' to U.S. national security."

The whistleblower further noted that during the time period starting in mid-May, Kurt Volker, U.S. special representative for Ukraine negotiations, and Gordon Sondland, U.S. ambassador to the European Union, met with members of the new administration in Kiev and "sought to help Ukrainian leaders understand and respond to the differing messages they were receiving from official channels on the one hand, and from Mr. Giuliani on the other."

The whistleblower also expressed confusion over Trump's mentioning in the phone call of U.S. cyber security firm CrowdStrike, which the Democratic National Convention (DNC) hired in 2016 to investigate hacks into its computers.

The whistleblower, also citing White House officials, said Trump asked Zelensky to "locate and turn over" the servers used by the DNC and examined by CrowdStrike. This request from Trump to Zelensky, according to the whistleblower, is meant to let the Ukrainian leader "assist in purportedly uncovering that allegations of Russian interference in the 2016 U.S. presidential election originated in Ukraine."

Trump suggested that Zelensky coordinate with Giuliani and Barr in this effort, according to the whistleblower.

"I do not know why the President associates these servers with Ukraine," the whistleblower wrote in a footnote in the complaint.

Trump in the phone call asked Zelensky to do the United States a "favor" by "getting to the bottom of" the matter, according to the transcript of the call.

"I would like you to find out what happened with this whole situation with Ukraine, they say CrowdStrike," said the president, "The server, they say Ukraine has it."