U.S. Attorney Joseph E. diGenova renewed his request yesterday for a judge to dismiss Mayor Marion Barry's suit alleging leaks by federal prosecutors of grand jury information, offering new evidence to rebut one of Barry's key allegations and denying claims that the current probe of D.C. contracting is racially motivated.

"Any alleged racial overtones respecting the current investigations of contracting practices of the District of Columbia government, or any earlier investigations, have been injected into this action and the media by {Barry} and by other District of Columbia officials . . . not by defendants or other federal government officials," diGenova said in response to friend-of-the-court papers filed last week by several civil rights groups.

DiGenova's new court papers, made public yesterday, are the latest volley since Barry filed suit last month seeking to stop what he said were leaks by prosecutors of grand jury information in an effort to undermine Barry's administration.

In court papers filed last week, Barry claimed that recent depositions by two Washington Times reporters in a civil libel suit against the newspaper by D.C. businessman John B. Clyburn, a key figure in the wide-ranging contracting probe, showed that a federal prosecutor and FBI agents gave information to the media about the drug-related death of Joann T. Medina.

But diGenova disclosed that no grand jury has investigated the December 1983 death of Medina, a close friend of Clyburn's, and therefore there could have been no leaks of secret information.

Barry has asked Chief U.S. District Judge Aubrey E. Robinson Jr. for a preliminary injunction to stop further disclosures about the contracting probes and about the relationship of Barry to convicted cocaine dealer Karen K. Johnson.

The mayor also has asked Robinson to make public all evidence now before the grand juries, to require "good faith" affidavits to support all future grand jury subpoenas and to impose sanctions against diGenova.

Robinson has not said whether he will hold a hearing on Barry's requests.

DiGenova said in the new papers that Barry "plainly" has not met the legal standard, set by the 11th U.S. Circuit Court of Appeals in a similar suit by former Carter administration official Bert Lance, of proving that the U.S. attorney's office had improperly disclosed secret grand jury testimony.

In that case, the appeals court set a five-part test for determining that a prima facie violation of grand jury secrecy rules had been made, and said such a violation must be shown even before there can be any legal discovery in the case.

Barry has asked Robinson to allow discovery, and his attorney Herbert O. Reid Sr. has indicated he might seek to gain information from news reporters about their sources.

DiGenova also argued that Barry has not shown that "leaks" have impaired his ability to govern.

"Common sense indicates that the very existence of a grand jury or other criminal investigation into contracting in the D.C. government (together with past convictions or guilty pleas of several D.C. government officials, including two deputy mayors), rather than leaks or the fear of a 'mishandled' investigation, could threaten the erosion in public confidence of which plaintiff complains," diGenova said.