President Trump's personal attorney Rudy Giuliani urged Arizona state legislators to get to the bottom of an alleged voter fraud conspiracy during a "hearing" Monday, the same day that the state certified the election for Democratic President-elect Joe Biden.

"You also had numerous situations of your workers, your citizens, observing the poll officials helping people vote to the point of telling them who to vote for," Giuliani said. "Poll workers being observed changing votes, taking ambiguous votes and making sure they were cast for Biden."

DISTRICT JUDGE HALTS 3 GEORGIA COUNTIES FROM ERASING DOMINION VOTING MACHINE DATA

Giuliani questioned retired Army Col. Phil Waldron, presented as a cybersecurity expert during the meeting, which was attended by Arizona state lawmakers and Rep. Paul Gosar, R-Ariz. Waldron also spoke at Giuliani's meeting about election fraud concerns with Pennsylvania state lawmakers last week.

Supporters of President Donald Trump protest in front of a local hotel where Arizona Republicans have scheduled a meeting as a "fact-finding hearing" to discuss the election, featuring members of Trump's legal team and Arizona legislators, Monday, Nov. 30, 2020, in Phoenix. (AP Photo/Ross D. Franklin)

Supporters of President Donald Trump protest in front of a local hotel where Arizona Republicans have scheduled a meeting as a "fact-finding hearing" to discuss the election, featuring members of Trump's legal team and Arizona legislators, Monday, Nov. 30, 2020, in Phoenix. (AP Photo/Ross D. Franklin)

Waldron warned of potential voter fraud in Arizona's Maricopa and Pima Counties, the state's two most populous counties, and said that Dominion's voting machines are vulnerable to hackers or on-site manipulation.

Waldron claimed that a Maricopa County official said the county did not validate signatures on some ballots, creating a "1.9 million vote fraud potential." That official has not produced an affidavit, he said. Waldron also claimed that a witness from Pima County said votes were "embedded" in various precincts to achieve a Biden win.

"What I take from your testimony, Colonel, is that 35,000 votes were embedded to each Democratic candidate in Pima County, the allegation by the gentleman who hasn't given us an affidavit," Giuliani said. "We don’t know if the gentleman is telling the truth or not."

TRUMP PRESSES GEORGIA GOVERNOR TO OVERRULE SECRETARY OF STATE, SCRUTINIZE BALLOT SIGNATURES

So far, courts and state and local election officials have not found evidence of widespread voter fraud, enough to overturn the results of the election. Biden ended up carrying the state by just over 10,000 votes, or three-tenths of one percent of the vote. Eleven electoral votes were up for grabs in Arizona.

Dominion, which is used by several states, has pushed back against such claims.

Michael Steel, a spokesman for Dominion, previously denied claims that votes cast through the company’s systems were at risk of being altered. He said it is physically impossible to alter votes in the system.

"Look, when a voter votes on a Dominion machine, they fill out a ballot on a touch screen. They are given a printed copy which they then give to a local election official for safekeeping. If any electronic interference had taken place, the tally reported electronically would not match the printed ballots. and in every case where we've looked at -- in Georgia, all across the country -- the printed ballot, the gold standard in election security, has matched the electronic tally," he said.

MCSALLY CONCEDES TO MARK KELLY IN ARIZONA SENATE RACE

Trump's defeat in Arizona - since the margin was greater than a tenth of one percent - doesn't qualify for an automatic recount. While there's no provision in the state for a losing candidate to request a recount, Arizona Republican Party Chair Kelli Ward has indicated the state party will file a challenge to the results after they were certified.

Amid the ongoing legal battle, the incoming Biden administration has received ascertainment from the U.S. General Services Administration as the apparent winner of the election, giving the green light to move ahead with transition proceedings.

CLICK HERE TO GET THE FOX NEWS APP

Fox News' Edmund DeMarche, Paul Steinhauser and Ronn Blitzer, and the Associated Press contributed to this report.