Congressional Republicans have ended their probe into allegations of political bias within the Federal Bureau of Investigation just days before Democrats take over the House of Representatives.

The investigation focused on whether or not the FBI and the Department of Justice exhibited bias when handling probes into former secretary of state Hillary Clinton's use of a private email server and President Donald Trump's relationship with Russia.

The probe was led by retiring Republican lawmakers Robert Goodlatte and Trey Gowdy. Goodlatte served as the chair of the House Judiciary Committee while Gowdy was the chair of the House Committee on Oversight and Government Reform.

Following the year-long investigation into the 2016 presidential candidates, House Republicans sent a letter to acting Attorney General Matthew Whitaker and other top Justice Department officials requesting they continue the investigation and appoint a special counsel to oversee the probe. They also requested that after the investigation has been closed, the Justice Department make all the documents available to the American people.

"The ramifications of decisions made and not made, the bias of some agents and attorneys involved, and the seemingly disparate treatment these investigations received have continued to reverberate into 2017, 2018, and potentially beyond," the letter reads.

In addition to the letter, Goodlatte also released a statement, in which he wrote that Clinton and Trump were "not treated equally" by the federal intelligence agencies. "The investigators in both investigations were biased against President Trump," the statement reads.

The Republicans pointed to the anti-Trump text messages sent between two FBI officials, Lisa Page and Peter Strzok, during the time of the investigation. Both Page and Strzok were forced out of the federal agency over the discovery of their private messages, in which the expressed dislike for the president.

In their conclusion of the probe into Clinton's emails, House Republicans expressed concern that former FBI Director James Comey was too lenient with the 2016 candidate when interpreting the law. The lawmakers are also worried that foreign officials may have gotten access to Clinton's messages.

In the incoming Congress, Democrats will have the power to issue subpoenas and launch investigations into President Trump and his administration. Rep. Jerry Nadler and Rep. Elijah Cummings are expected to replace Goodlatte and Gowdy as chairs of the House committees.

Cummings has already sent over 50 letters to the White House, Congress and other federal agencies requesting full compliance with the committee's requests for documents and interviews. Topics to be examined by House Democrats include the Flint water crisis, hurricane relief and immigrant child separations.

"Many of these requests were bipartisan, and some are now more than a year old. As Democrats prepare to take the reins in Congress, we are insisting—as a basic first step—that the Trump Administration and others comply with these Republican requests," Cummings wrote in a statement.

Nadler has criticized Republicans for carrying out their investigation into FBI bias, claiming that the probe was conducted to undermine the integrity of special counsel Robert Mueller and his Russia investigation.

"These are blatant attempts to distract from and undermine the credibility of Special Counsel Mueller. Chairman Goodlatte and Chairman Gowdy are simply off base — just as they were last year, when they called for a new special counsel to investigate a slew of Hillary Clinton conspiracy theories. Where there is no crime, there is no criminal investigation for a second special counsel to manage," Nadler wrote in a statement earlier this year.