Three previously uncounted batches of votes have now been discovered in Georgia, narrowing Joe Biden's lead over Donald Trump by more than 1400.
The three caches of votes in Floyd, Fayette and Walton Counties, found during the state's recount, heavily favoured the President, although they are not even close to overcoming his deficit of more than 12,000 votes.
Meanwhile, Georgia Republican Party chairman David Shafer said a 9626 vote error had been picked up during the hand recount in DeKalb County.
"One batch was labelled 10,707 for Biden and 13 for Trump – an improbable margin even by DeKalb standards," Shafer said on Twitter.
"The actual count for the batch was 1081 for Biden and 13 for Trump. Had this counting error not been discovered, Biden would have gained enough votes from this one batch alone to cancel out Trump's gains from Fayette, Floyd and Walton."
In a sworn affidavit, the Republican observer described how he only picked up the error by observing the numbers written on the sheets attached to the boxes of ballots.
DeKalb County chief executive Michael Thurmond said in a statement he had launched a preliminary investigation into the accuracy of Shafer's "unsubstantiated tweet", and that elections officials "have not verified the allegation".
"Based on Chairman Shafer's Twitter storm, the alleged 'vote error' was discovered, reported to DeKalb elections officials and corrected prior to the transmission of the official audit report to the Georgia Secretary of State's Office," he said.
"If the scenario occurred as Chairman Shafer alleges, this is evidence that the checks and balances, established by Georgia Secretary of State Brad Raffensperger to ensure the accuracy of the election results, performed as designed."
Shafer replied, "The affidavit that we submitted identifies the batch of ballots by scanner and box number. What does it mean when DeKalb County says it cannot 'verify' our account of the error? Is the paperwork missing? Are the ballots gone? Where have they looked? Who have they interviewed?"
Separately, lawyer L. Lin Wood has filed a number of affidavits in his lawsuit against the Georgia Secretary of State, as he seeks an emergency order blocking the certification of the results.
Nine of the witnesses to the recount process claimed to have seen suspiciously pristine mail-in ballots, almost all for Biden, with voting bubbles perfectly filled in – as though they had been printed or machine stamped.
"I observed that the markings for the candidates on these ballots were unusually uniform, perhaps even with a ballot marking device," poll worker Susan Voyles said in one statement.
"By my estimate in observing these ballots, approximately 98 per cent constituted votes for Joe Biden."
Republicans have touted the ongoing developments in Georgia as evidence that Trump still has a chance.
Earlier this week the head of Arizona's Republican Party has insisted "the election is far from over", while the President hailed a "big victory" in Nevada.
Biden currently leads Trump by 10,377 votes – just 0.3 percentage points – in Arizona, which has not voted for a Democratic presidential candidate since Bill Clinton in 1996.
It's one of a number of key battleground states where the Trump campaign and Republicans have alleged widespread voter fraud, and are attempting to overturn the results through a combination of legal challenges and requests for recounts and audits.
Unlike many other states, Arizona does not allow recount requests and its threshold for automatic recounts are much stricter, requiring the vote difference to be less than 0.1 per cent.
In the video, Dr Ward referred to a viral 2017 tweet from Arizona's Democratic Secretary of State Katie Hobbs – responsible for overseeing elections – who described Trump's base as neo-Nazis.
"That doesn't speak to being unbiased to me. Does it to you?" she said.
"I think it's something that we have to be very, very cognisant of. We're going into the canvassing phase of this election. That means we're assuring that the votes cast are cast as the voter intended and counted appropriately. We have questions that have to be answered."
Ward said she was working "hand-in-hand" with the Trump campaign and his legal team, including Rudy Giuliani and Sidney Powell, "to make sure that the elections in Arizona have integrity".
On Tuesday, Giuliani made his first appearance in court for the Trump campaign's Pennsylvania lawsuit, where he alleged "widespread national voter fraud".
At the same time, the state's Democratic-majority Supreme Court knocked back a separate case which alleged poll watchers were illegally prevented from observing the counting process.
The Arizona Republican Party filed a lawsuit last week demanding a hand recount of votes by individual precinct rather than "voting centres", which were introduced by the state's most populous county, Maricopa County, for the 2020 election.
A hearing in that case is scheduled for Wednesday afternoon.
That came as a separate lawsuit requesting reinspection of ballots with "over votes", which occurs when the voter marks more candidates than is allowed, was tossed out by a judge.
Meanwhile, three Arizona Republican Congressmen, Andy Biggs, Paul Gosar and David Schweikert, have called for a "100 per cent audit" of all ballots in Maricopa County.
In a letter to the Maricopa County Board of Supervisors on Friday, the trio said "hundreds" of residents had signed affidavits alleging their ballots "may have been discounted".
They cited the narrow margin between the two candidates, "together with questions regarding anomalies and potential errors", as "more than enough" justification to commence an audit of the ballot images.
In a video released this week, which also raised questions about Dominion Voting Systems, Biggs described the election as "a joke".
On Monday, Trump hailed a "big victory" in Clark County, Nevada – which takes in Las Vegas – after election officials threw out the results of a county commissioner race due to voting "discrepancies".
"Big victory moments ago in the state of Nevada," the President tweeted.
"The all Democrat County Commissioner race, on same ballot as President, just thrown out because of large scale voter discrepancy. Clark County officials do not have confidence in their own election security. Major impact!"
The Clark County Commission cited the narrow 10-vote margin between Democrat Ross Miller and Republican Stavros Anthony, as well as a number of discrepancies including six people who voted twice, as justification for a possible re-run of the single local election.
"We have found discrepancies that we can't explain that would cast a doubt on whether or not that margin of victory is solid," Registrar of Voters Joe Gloria told commissioners.
"That's the only race in the entire election we have any concern related to the outcome. And it's because of the margin."
They certified the presidential election results, where Biden beat Trump by 33,596 votes.
Still, Trump's allies have seized on the news.
Former Nevada Attorney-General Adam Laxalt said the election represented 153,000 votes, or one sixth of the county's total.
Former Acting Director of National Intelligence Ric Grenell, who is working with Laxalt on the Trump campaign's legal challenges in Nevada, said "you have to suspend common sense to believe fraud only happened on one race of a long ballot".
"They didn't have faith in their election – there were too many discrepancies," he tweeted. "They threw out 150,000 ballots over 10 cases? Absurd."
The Democratic candidate was declared the presumptive winner of the 2020 election after edging ahead of Trump in key battleground states including Pennsylvania and Georgia in the days after the election, as batches of absentee ballots continued to be counted.
Trump has so far refused to concede, claiming the election was "rigged" and vowing to exhaust his legal avenues.
Time is running out for the President, with the electoral college due to meet in each state on December 14 and formally vote on the winner.