A federal district court judge in New York last week threatened Alan M. Dershowitz, professor of Law, with possible disciplinary proceedings after Dershowitz charged that the U.S. attorney's office had "deliberately" withheld evidence from the Supreme Court.

Judge Arnold Bauman told Dershowitz last Wednesday that he would consider beginning the proceedings against the Harvard professor if "the deadly serious charge was not proved."

Dershowitz declined yesterday to comment on the substance of Bauman's threat, but said that he has retained counsel to represent him during all future proceedings in Bauman's court.

"Since the judge specifically considered imposing discipline on me, it was judged necessary by me and my advisors that I be represented in all further proceedings," he said.

Dershowitz will be represented by Monroe Freedman, dean of the Hofstra Law School and a leader of the American Civil Liberties Union, when court resumes session on Monday.

The charge against the U.S. attorney's office was made by Dershowitz during a hearing aimed at winning a new trial for his client, Edmund A. Rosner. Rosner was convicted in 1972 on charges of bribing a police officer in order to obtain secret grand jury materials.

The chief prosecution witness during the 1972 trial, Det. Robert S. Leuci, recently admitted perjuring himself during Rosner's first trial, but still maintains that Rosner tried to bribe him. In 1972, Rosner claimed that Leuci "pressured" and entrapped him into the bribe.

A memorandum submitted to the court as evidence last week indicates that the prosecuter's office had knowledge of Leuci's perjury, but did not make this information known when Rosner appealed his conviction to the Supreme Court last April.

Throughout the current round of hearings, Dershowitz has claimed that the prosecution "covered up" Leuci's criminal activity in order to maintain Rosner's conviction. Leuci, who was acting as a federal agent during the time of Rosner's arrest, has acknowledged that he shared $200 stolen during an illegal narcotics search and that he served as a "middle-man' in a series of illegal payoff schemes.

At next Monday's hearing, the first since Bauman leveled his threat at Dershowitz, Rosner's attorney will continue his efforts to show that the U.S. Attorney for the Southern District of New York purposely concealed evidence.

Rosner said yesterday that Dershowitz's allegation "has already been proven, and it will be further proven."

Both Dershowitz and Rosner said they will take their motion for a retrial back to the Supreme Court if necessary. "I'm confident that ultimately I'll succeed," Rosner said yesterday.