A federal grand jury in New York is hearing new evidence this week as part of the investigation into Sean "Diddy" Combs.

Attorney Ariel Mitchell told NBC News on Wednesday that a male client of hers is testifying before a grand jury in the Southern District of New York on Thursday.

A source familiar with the grand jury proceedings confirmed that a male is expected to testify Thursday.

NBC News has reached out to Combs' legal team for comment. A spokesperson for the U.S. Attorney's Office declined to comment.

Combs has pleaded not guilty to charges of racketeering, sex trafficking and transportation to engage in prostitution. Assistant U.S. Attorney Emily Johnson said at a hearing earlier this month that a superseding indictment could affect the length of his trial, which is expected to begin on May 5.

Combs is currently being held at Brooklyn's Metropolitan Detention Center. His legal team is seeking to appeal his detention, which has been denied twice by two separate judges.

Amid Combs' looming criminal trial, the embattled mogul has been hit with a wave of civil lawsuits. Texas based attorney Tony Buzbee filed the most recent cases against Combs on Monday in New York state’s Supreme Court. The two separate lawsuits accuse Combs of sexually assaulting two boys, one who was 10 at the time and another who was 17. The plaintiffs allege the abuse occurred in 2005 and 2008, respectively. Combs has denied the allegations.

In a statement this week, Combs' team said, “The lawyer behind this lawsuit is interested in media attention rather than the truth, as is obvious from his constant press appearances and 1-800 number.”

The statement went on to say: “As we’ve said before, Mr. Combs cannot respond to every new publicity stunt, even in response to claims that are facially ridiculous or demonstrably false. Mr. Combs and his legal team have full confidence in the facts and the integrity of the judicial process. In court, the truth will prevail: that Mr. Combs never sexually assaulted or trafficked anyone — man or woman, adult or minor.”

Combs is facing over a dozen civil suits but has only settled one, which was filed by his ex-girlfriend Casandra Ventura last year. In her suit she accused Combs of years of physical and sexual abuse. Combs denied the allegations and settled for an undisclosed sum. Several months later, surveillance footage obtained by CNN showed Combs brutally beating Ventura in 2016 in a hotel hallway. In a video posted to his social media, Combs apologized for the incident and said he had since changed.

Prosecutors revealed in their sweeping criminal indictment against Combs that the video of Ventura and her claims are part of their case against him.