Despite an invitation from Sen. Rand Paul, R-Ky., on Wednesday to testify before a Senate subcommittee about possible privacy and unmasking abuses perpetrated by Joe Biden and the Obama administration, Acting Director of National Intelligence Richard Grenell will not be appearing before Congress to discuss the issue, Fox News has learned.

A senior administration official with knowledge of the situation told Fox News on Wednesday that after receiving Paul's request, Grenell declined the offer to testify. The official also said Grenell is going to be continuing his efforts to be transparent and will continue to be responsive to congressional requests for documents, but will not appear for testimony.

Top Obama administration officials had purportedly requested to "unmask" the identity of former National Security Adviser Michael Flynn during the Trump administration's transition period, after his phone conversation with the Russian ambassador, according to a list of names from that controversial process that was made public.

During a press conference on Wednesday, Paul highlighted these revelations and claimed Grenell's testimony would be crucial to finding out the truth.

"The fact that Vice President Biden and all of the president's inner circle, President Obama's inner circle, individually requested to unmask Gen. Flynn is very troubling," he said. "Unmasking involves revealing the identity of an American's private phone conversation without a constitutional warrant to eavesdrop on that conversation."

Paul added, "That's why today I'm inviting the director of national intelligence to come to testify next week on these troubling declassified documents that now show that Vice President Biden and virtually the entire top echelon of the administration of President Obama was listening to an Americans conversation without a constitutional warrant unmasking him and listening to a top adviser of an incoming president of the opposite party."

GRAHAM CALLS ON ACTING DNI GRENELL TO 'RELEASE THE NAMES' OF THOSE WHO REQUESTED 'UNMAKING' OF FLYNN

In addition to Biden, those who reportedly sought to unmask Flynn's identity include former Federal Bureau of Investigation (FBI) Director James Comey, then-CIA Director John Brennan, then-Director of National Intelligence James Clapper, and Obama's then-chief of staff Denis McDonough.

Paul had sent a letter to Attorney General Bill Barr and Grenell on Tuesday, asking for any declassified materials on the subject that had been sent to the Department of Justice (DOJ), and anything related to Foreign Intelligence Surveillance Act (FISA) abuses.

"While some individuals have claimed that unmasking relating to Gen. Michael Flynn was legitimate, Congress is unable to draw final conclusions without the recent documents that you have declassified," the Kentucky Republican wrote.

"I hereby request the information you recently turned over to the Department of Justice on this matter, including information about the participants in this abuse, the names of those who were unlawfully unmasked, and the use of that information. Again the American public entrusts Congress with oversight, and I appreciate your prompt response on this pressing matter."

Paul claimed that the evidence shows Biden has been caught "red-handed" and accused the 2020 presidential candidate of being "in this up to his eyeballs."

"Think about it, remember we went through this thing called impeachment. They said President Trump was using the government to go after a political opponent," he said during the presser. "This is Vice President Biden using the spying power to the United States to go after a political opponent. He's caught red-handed here, Vice President Biden's caught red-handed eavesdropping on political opponents' phone calls. That to me is alarming."

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Paul also appeared on Fox News' "Your World with Neil Cavuto" on Wednesday, and said if Biden turns out to have been deeply involved in the scandal, it should disqualify him from holding the office of the presidency.

"This was a conspiracy. And really, the question is, did President Obama direct it all, or did Vice President Biden?" he asked. "We now know for a fact Vice President Biden was involved and he needs to be questioned on this, because we can’t elevate someone to the presidency who's willing to use the intelligence community to spy on his political opponents. That should be a deal-killer."

Fox News' Chad Pegram and Andres del Aguila contributed to this report