Ever since the whistleblower complaint focused on President Donald Trump's Ukraine call was released to the public, he and his allies have repeatedly questioned how the intelligence community handled the matter -- trying to discredit the account because it's based on second-hand information -- not direct, first-hand knowledge of the alleged wrongdoing.

GOP Sen. Lindsey Graham, R-S.C., and the president's other defenders claimed on weekend news shows that rules they said required a whistleblower to have first-hand knowledge were changed, just before the complaint, was filed to allow second-hand information -- and Trump did so himself on Monday.

“WHO CHANGED THE LONG STANDING WHISTLEBLOWER RULES JUST BEFORE SUBMITTAL OF THE FAKE WHISTLEBLOWER REPORT? DRAIN THE SWAMP!,” Trump tweeted Monday morning.

The complaint, which prompted an impeachment inquiry, was based largely on second-hand knowledge the whistleblower said was gained from other U.S. government officials, and it alleged that Trump abused his office in the July 25 call by repeatedly pressuring Ukraine's president to work with his personal attorney Rudy Giuliani and Attorney General William Barr to investigate former Vice President Joe Biden.

The president's supporters have claimed that, in August, prior to the whistleblower filing his complaint about Trump and the July call, the intelligence community changed a rule they say required that whistleblowers provide direct, first-hand knowledge of alleged wrongdoings.

In making the claim, Trump and his supporters referred to a change made on the “Disclosure of Urgent Concern” form, which previously had asked if the whistleblower had direct or indirect knowledge.

The intelligence community inspector's general's office released a statement Monday evening disputing any recent change in the whistleblower form.

“With respect to the whistleblower complaint received by the ICIG on August 12, 2019, the ICIG processed and reviewed the complaint in accordance with the law,” read a statement from the intelligence community inspector general's office (ICIG) dated Sept. 30. “The Disclosure of Urgent Concern form the Complainant submitted on August 12, 2019 is the same form the ICIG has had in place since May 24, 2018,” the statement said.

National security lawyers who specialize in whistleblower complaints told ABC News that whistleblowers have never been required to have direct knowledge of alleged wrongdoing in order to file a complaint.

“In no way, shape or form was anything changed as a matter of law,” said national security lawyer Brad Moss. “The law has never said that a whistleblower couldn't have second information because that would unnecessarily restrict an inordinate amount of whistleblowing allegations coming forward because most people don’t have the first-hand information.”

Irvin McCullough, national security analyst for Government Accountability Project, said that the change made in an attempt to revamp and simplify the form, carried no legal weight and did not change any whistleblower laws or protections.

Moss agreed, saying that the previous form caused some confusion for whistleblowers who did not have legal counsel about whether they themselves had to have first-hand knowledge. He agreed as well that changing the form didn't change the law that he said clearly allows a whistleblower to file a complaint with second-hand information.

“The changed form didn’t change anything as a matter of law, nor could they change the law with just a form,” Moss said. “If they wanted to revise the evidentiary threshold that the ICIG [intelligence community inspector general) had to meet, then Congress had to change the law -- it couldn’t be done through a form.

Beyond that, the ICIG's statement stated that some of the information in the whistleblower's complaint did in fact come from first-hand knowledge.

"The Complainant on the form he or she submitted on August 12, 2019 in fact checked two relevant boxes: The first box stated that, ‘I have personal and/or direct knowledge of events or records involved’; and the second box stated that, ‘Other employees have told me about events or records involved,’” the ICIG's statement said.

It continued: "As part of his determination that the urgent concern appeared credible, the Inspector General of the Intelligence Community determined that the Complainant had official and authorized access to the information and sources referenced in the Complainant’s Letter and Classified Appendix, including direct knowledge of certain alleged conduct."

McCullough explained that to file a complaint a whistleblower is required only to have “reasonable belief” of wrongdoing and that, once the complaint is filed, it is up to the inspector general to acquire first-hand information and whether to deem the complaint credible.

“What the old form purported to explain to the whistleblowers was that the ICIG could not find their information credible unless they obtained first hand knowledge of the wrongdoing,” McCullough said.

“This isn’t about the law anymore,” Moss said on why he believes Trump and his supporters are spreading this claim. “This is about political persuasion. It is a good political smear tactic to use to get their allies on board as long as possible and to muddy the waters.”