Attorney General William Barr has allowed the Department of Justice (DOJ) to investigate any "substantial allegations" of voter fraud in this year's presidential election.

Barr said Monday that investigations could take place as long as there is an allegation with a credible basis. He added that this could possibly affect the result of a federal election in an individual State if true.

"Nothing here should be taken as any indication that the Department has concluded that voting irregularities have impacted the outcome of any election," Barr said in a The Hill report.

Democratic nominee Joe Biden was forecasted by every major news outlet as the presidential election winner on Saturday. However, President Donald Trump has implied that he will not concede.

Trump continues to claim that there was widespread voter fraud during this year's election. The Trump campaign team has filed lawsuits in many swing states that Biden won.

The team has asked local judges to either invalidate or stop counting the mail-in ballots. Mail-in ballots have reached a historical record for the number of ballots cast due to the COVID-19 pandemic.

Some Republicans have supported Trump's allegations of voter fraud in this year's election. Others moved on to congratulating Biden on winning the presidential seat.

Senate Majority Leader Mitch McConnell said that states have yet to certify their election tallies.

"We have at least one or two states that are already on track for a recount and I believe the president may have legal challenges underway in at least five states," McConnell noted in a report.

Related story: McConnell Wins the Senate Race Against McGrath

Meanwhile, Richard Pilger, the director of the Election Crimes Branch in the DOJ, has resigned hours after Barr issued a memo to federal prosecutors to investigate voter fraud claims.

His resignation email did not mention whether he plans to stay in the department in another capacity. But he sent a memo to his colleagues suggesting that his resignation was likely linked to Barr's directive.

Pilger told colleagues that Barr was issuing an important new policy for ballot investigations. He added that he enjoyed working with them for more than a decade to "diligently enforce federal criminal election law, policy, and practice without partisan fear or favor."

Barr released the memo without anyone's direction, according to one of the department's officials, as reported by CNN. However, the report added that the memo's purpose is unclear, with prosecutors already knowing their responsibilities to probe vote fraud and other election irregularities.

Some Justice officials claimed that Barr had been obsessed with the idea of voter fraud in recent weeks. They added that he has repeatedly asked about prosecutors' efforts to look for signs of voter fraud.

Barr has also asked about the possibility of sending armed federal officers to guard the polls. The DOJ earlier issued a directive to federal prosecutors that allowed deploying armed federal officers to polling locations across the country as ballots were being counted. 

Trump's Voter Fraud Claims

Trump has reiterated several times the possibility of vote fraud even before the election day. His campaign set up a hotline in an attempt to uncover evidence of voter fraud during this year's election. 

Related story: Trump Repeats Claims of Fraud as Pennsylvania, Nevada, Georgia Side With Biden

Rudy Giuliani, Trump's personal lawyer, tweeted the phone number, adding that American voters could call to share their experiences with election irregularities. But this was met with a series of prank calls, according to an Aljazeera report.

One of the most notable prank callers was Alex Hirsch, known for creating the animated television series "Gravity Falls."