A federal grand jury in New York will hear new evidence in the criminal case against Sean "Diddy" Combs, according to sources familiar with the matter.

The grand jury is expected to convene Thursday, the sources said.

The sources declined to describe what the new evidence is or who might be called to testify about it.

Federal prosecutors have previously raised the possibility of additional charges against Combs.

A spokesman for the U.S. Attorney's Office for the Southern District of New York declined to comment.

His trial is scheduled for May, but prosecutors have suggested the timing or duration of the trial could change if they opt to add charges.

Combs has denied all of the allegations against him -- in both criminal and civil cases. In the wake of the criminal case, many individuals have filed civil lawsuits against the music producer.

In a statement Monday, his defense attorneys hit back against new allegations included in a civil suit against the rapper -- including one involving the sexual assault of a 10-year-old boy -- accusing the plaintiff's lawyer of lacking credibility.

"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 said. "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."

The defense attorneys said they and Combs "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," the defense attorneys said.

As for the criminal case, Combs has already pleaded not guilty to racketeering conspiracy, sex trafficking and prostitution charges and is being held without bail, over the objection of his attorneys.

As part of his defense, Combs' attorneys have asked the judge to order federal prosecutors to disclose the identities of his accusers.