James and Lonise Bias, the parents of University of Maryland basketball star Len Bias, are concerned that "constant leaking" of unsubstantiated information "may have tainted" the grand jury investigation into the death of their son, the family's attorney said last night.

Wayne Curry, issuing one of the family's few public statements since Bias died of cocaine intoxication on June 19, expressed unhappiness with "the proliferation of innuendo" resulting from comments by Prince George's County State's Attorney Arthur A. Marshall Jr. that have been reported by the news media.

"They are concerned that the constant leaking of alleged evidence by poorly informed, uninformed or speculating individuals may have tainted the grand jury process," Curry said.

"The tying of Len's tragic death with other matters which are apparently unconnected, such as gambling or unconnected drug investigations, may prejudice views held by the public, including grand jury members."

The county grand jury investigating Bias' death and possible drug use among Maryland athletes begins hearing testimony today that will determine whether criminal indictments for possession of drugs will be issued against any persons who either supplied cocaine to Bias or were using it with him before he died.

Curry said Bias' parents are "hopeful that the investigation will unearth the truth and that others will not continue to bury their own culpability in his coffin . . . . Whatever happened there is not confined to Len Bias."

He added, "The people and players who were Len's friends have been instructed not to talk. Considering how close they were to Len and his family, that's painful by itself."

Bias collapsed at about 6:30 a.m. on June 19 in the Washington Hall dormitory suite he shared with Terry Long, David Gregg and three other teammates.

Long, Gregg and Brian Lee Tribble, a longtime friend of Bias, were with him in the dormitory suite at the time.

Marshall said last week "evidence will show" that Tribble brought drugs into the room. Long, Gregg and Tribble have declined to comment, on the advice of their attorneys.

Prosecutors said the grand jury will investigate whether Maryland basketball coach Lefty Driesell or Bias' coach at Northwestern High School in Hyattsville, Robert Wagner, told players to remove drugs or drug paraphernalia from the dormitory suite. Such directions could lead to obstruction-of-justice charges against the coaches, Marshall has said.

Driesell assembled the team at his house shortly after Bias was pronounced dead at Leland Memorial Hospital in Riverdale. According to several players, Driesell advised the team not to talk publicly about Bias' death.

Marshall has said the grand jury will investigate Driesell's conduct, possible drug use by team members, and allegations that athletes may have tried to alter drug tests and that a player may have bet on a Maryland basketball game last season.

"Telling the grand jury what will not be explored before the evidence has been presented does not engender confidence that every possibility will be explored to a reasonable conclusion," Curry said. "The family continues to pray for the truth."

Marshall was out of town and could not be reached for comment last night.

Sixty-five witnesses may be called before the grand jury this week, Assistant State's Attorney Jeffrey Harding said. Tribble has not been subpoenaed.

Under Maryland law, persons who testify before a grand jury investigating drug crimes receive automatic immunity from prosecution for related drug offenses. Prosecutors have said they are uncertain whether Long or Gregg will be called to testify.

Marshall has freely discussed some evidence gathered during the investigation, but has kept quiet about at least two pieces of information the 23 grand jurors will hear: whether there is physical evidence linking Tribble, Long and Gregg to drugs and paraphernalia found in a dumpster behind Washington Hall and in Bias' leased sports car; and the identities of two women who have talked to investigators and who Marshall said were in the dormitory suite at some point during the night.

University police who searched the dumpster found a glass vial containing 0.15 gram of cocaine, cut straws with cocaine residue, a pipe that can be used to smoke cocaine and empty bottles of malt liquor and cognac.

State police found traces of PCP in one of the bottles. Police found about 12 grams of "very high quality" cocaine in Bias' car the day after his death, a source close to the investigation said.

Prosecutors hope to reconstruct for the grand jury the last hours of Bias' life, from about midnight June 18, shortly after he and his father returned from Boston -- and negotiations with the Boston Celtics, who had just made him their top pick in the National Basketball Association draft -- until about 6:32 a.m. June 19, when a man who identified himself as Brian Tribble called the county's 911 emergency number asking for help.

Marshall said he will first let the grand jury listen to the 911 tape, then summon as witnesses paramedics who responded to the call, state medical examiners and police.

Marshall said he believes that Bias made several stops after leaving his parents' house in Landover shortly before midnight, but that Bias did not use drugs until he returned to his room on the College Park campus sometime after 3 a.m.

Information that supports his theory, Marshall said, came from a Southeast Washington woman who told police Bias visited her between 2 and 3 a.m. on the morning of his death.

Bernadette Holton, 41, said Bias stayed for about an hour, borrowed $310, made a phone call and then left in his car, saying he "had to meet some people." Bias had about $100 when he died, a law enforcement official said.

Bias did not appear to be under the influence of drugs or alcohol, Holton said in an interview last week, but he did seem "tense" as a result of his heavy travel schedule.

Holton said she has known Bias for about 2 1/2 years.

In a four-page statement given to police on June 26, Holton, who has had some training as a nurse, said that Bias asked her last spring for "Black Beauties," an amphetamine, and for a diuretic. "He said he hadn't used it before, but that he knew it was speed and he needed an energizer to study for finals," Holton said during the interview last week. "I asked him what the fluid pill was for, and he said to flush out his system. I said no."

Marshall has said some Maryland athletes may have used diuretics to try to alter random drug tests, allegations that the grand jury is to hear during an August session.