A Republican congressman made the bombshell charge that there is 'growing evidence' the FBI secretly altered witness reports in their investigations into Hillary Clinton's email server and Russia's role in the 2016 election.

Rep. Mark Meadows, the chairman of the conservative Freedom Caucus and leading voice for the right in the House of Representatives, asked Justice Department Inspector General Michael Horowitz to investigate the witness forms, known as 302s, that are used by the FBI to record activity in their investigations.

During Tuesday's joint hearing of the House Judiciary and Oversight Committees, Meadows alleged the FBI may have changed the forms used to record witness interviews.

Rep. Mark Meadows charged there is 'growing evidence' the FBI secretly altered witness reports in their investigations into Clinton's email server and Russia's role in the 2016 election

Inspector General Michael Horowitz said his team is following-up on the reports

'There is growing evidence that 302s were edited and changed and it gets back to … those particular interview sessions and those 302s. It is suggested that they were either changed to prosecute or not prosecute individuals. And that is very troubling,' Meadows told Horowitz.

Horowitz suggested the inspector general's office were already looking into the matter, saying his team is following up on that.

'We have been getting those kinds of referrals and as often happens when we issue reports like this, we get other information coming to us. We are intending to follow-up on that,' he said.

Meadows also went back to one of his Republican colleague's questions and asked why the FBI didn't record their interviews with key witnesses — which Horowitz said was standard procedure.

Republicans spent most of Tuesday's hearing, which lasted about seven hours, digging into the reports details to question Horowitz on whether or not actions taken by the FBI were political in nature.

On Thursday, Horowitz's office released a scathing report that documented FBI officials' mishandling of the Clinton investigation. It also contained transcripts of several text messages that FBI officials and attorneys sent criticizing President Donald Trump.

But while the report criticized the FBI's handling of the investigation it noted the actions were not politically motivated.

Meadows told reporters after the hearing that he has seen evidence that the 302s filled out during the Clinton and Russia investigations have been changed.

He also said he has 'more information' about the alleged alterations but, thus far, has not provided any details.

His office did not respond to the DailyMail.com's request for more information on the allegations.

Tuesday marked the second day Horowitz went before lawmakers on Capitol Hill to address his report.

Reporter Sara Carter, a Fox News contributor, had first brought up altered 302s during her appearance with host Sean Hannity in January, The Hill newspaper noted.

'There are indicators right now that [FBI Deputy Director Andrew] McCabe may have asked FBI agents to actually change their 302s. Those are interviews with witnesses. So basically, every time an FBI agent interviews a witness they have to go back and file that report,' Carter told Hannity.