NEW YORK, DEC. 23 -- Brooklyn District Attorney Elizabeth Holtzman, who has been touted as a candidate for higher office, has suffered a serious setback in making an unfounded attack on a judge.

A judicial investigation concluded this week that Holtzman had falsely accused the judge, Irving W. Levine of Brooklyn, of humiliating a sexual assault victim by forcing her to get down on her hands and knees to reenact the alleged rape. The state's chief administrative judge has asked Charles J. Hynes, the special state prosecutor who tried the Howard Beach slaying and assault case, to examine Holtzman's conduct.

Holtzman, who was a Democratic member of the House of Representatives from 1973 to 1980, has built a political career on defying the Brooklyn Democratic clubhouse. By attacking a judge, who comes from the party establishment, without having all the facts, she has left herself vulnerable to criticism.

Holtzman has been elected twice to the prosecutor's post after losing a three-way Senate race to Alfonse M. D'Amato (R-N.Y.) in 1980. She has long been viewed as a potential candidate for mayor or state attorney general, but the furor over the rape case victim has clouded her political prospects.

"I understand that this process has caused pain to a number of people; I deeply regret this," Holtzman said in a statement. She said she had "an obligation to act on serious and credible allegations of misconduct brought to my attention," and said that she "acted out of deep concern for the treatment of sexual assault victims."

But attorney Richard Emery, a longtime Holtzman critic, said she was mainly interested in making headlines. He said Holtzman had been "blatantly hypocritical" by "asserting the rights of victims and then abusing the victim herself . . . . She presumed Levine guilty, called him a deviant. A prosecutor should know you've got to do the proper investigation."

The flap began Dec. 1 when Holtzman publicly accused Levine of having "degraded, humiliated and demeaned" a complainant in a sexual misconduct trial by having her get down on all fours to reenact the alleged assault.

"Making her relive the anguish of the experience so graphically and forcing her to do so before a group of strangers" turned the trial into "an avenue for inappropriate sexual titillation," she said in a letter to a judicial committee.

When other participants in the case challenged Holtzman's account, she played for reporters the audio portion of a videotape on which a Brooklyn woman swore that the judge made her reenact the rape. But the victim later retracted her account and claimed she had been coerced by the prosecutor's office, a charge that Holtzman denied.

This week's report by Administrative Judge Robert G.M. Keating concluded that Holtzman made her charges without reading the trial record, without questioning the victim, and without interviewing the judge, the defense lawyer, the prosecutor or other participants.

A transcript shows that it was the defense lawyer who suggested the woman get down on all fours, and that Levine said "Hold it" and elicited what the report called "a verbal description" of the attack.

Holtzman supporters said a witness' sworn account is often considered sufficient to make an arrest and that she also relied on an affidavit from the assistant district attorney, Gary A. Farrell, in the case. They said Holtzman had received other allegations against Levine, including one that he napped on the bench.

But the New York news media, which have never had a warm relationship with Holtzman, have been swift to write her political obituary. "I think she's been mortally damaged," Emery said. "She doesn't have any political future."

Leonard L. Finz, the sexual assault victim's attorney, said that Holtzman "acted very precipitously and before she had all of the facts at hand . . . . The judge was a victim of those charges."