Harvey Weinstein has been hit with new criminal charges, a prosecutor said on Thursday, as the Manhattan district attorney's office prepares to retry the former movie mogul following the reversal of his rape conviction.

Jurors in Manhattan found Weinstein, 72, guilty on rape charges in 2020, but the New York Court of Appeals threw out the conviction in April, finding Weinstein did not get a fair trial because a judge improperly allowed testimony by accusers he was not formally charged with assaulting.

Manhattan prosecutors said in July that they were investigating additional violent sexual assaults allegedly committed by Weinstein after more women agreed to testify against the Miramax studio co-founder. He has denied ever having non-consensual sexual encounters with anyone.

During a hearing before Judge Curtis Farber in New York state court in Manhattan on Thursday, prosecutor Nicole Blumberg said a grand jury had indicted Harvey Weinstein on additional charges, but did not specify what those crimes were.

Weinstein was not in court for the hearing. He was rushed to the hospital from New York City's Rikers Island jail on Sunday to undergo emergency heart surgery, and his lawyers say he is beset with health problems.

Weinstein's defence lawyer Arthur Aidala said the grand jury was probing three "matters," but did not know whether that referred to specific incidents or the number of accusers.

Farber has tentatively set a trial date for Nov. 12. Blumberg said on Thursday that prosecutors would still be prepared to go to trial on that date. Aidala told reporters his team would try to delay any trial containing new charges.

Despite the reversal of his New York conviction, Weinstein has remained in custody in New York because of a separate rape conviction in California.

At the hearing, Farber ordered that Weinstein remain in custody at Bellevue Hospital, finding that the latest health care showed he was not getting adequate treatment at Rikers.