Districts of Columbia officials continued their search yesterday for an 8-year-old heroin addict who police believe was the subject of a story on juvenile drug abuse in Sunday's editions of The Washington Post. No new leads were reported.

Earlier claims by Mayor Marion Barry that "We already know" who the child is turned out to be premature, as the mayor's press secretary ackowledged that no one in city government, including the mayor, knows the name of the child or his whereabouts.

"The mayor does not know the name or home address of the boy and neither does anyone else in the government," mayoral spokesman Alan F. Grip said.

Only Alyce Gullatte, a psychiatriast and drug-abuse counselor at Howard University, knows the child, Grip said. Gullatte, who has known the family for some time, "has emerged as the key to this entire mystery," Grip said.

Gullate has told Barry that the child's mother called her Tuesday morning and said that she and the child had "left home. . .because she doesn't want to be arrested or have the child taken away from her," the mayor said Tuesday.

Yesterday, Barry asked Gullatte to begin helping city police officials and social workers from the Department of Human Services, who have been looking for the child since Monday, but apparently without the assistance of Gullatte's knowledge.

Sunday's story of the 8-year-old, identified only as "Jimmy," told of a world of heroin addiction that began at age 5 when the boyfriend of the boy's mother allowed the child to sniff heroin. Now the child is a third-generation heroin addict and receives daily injections, sometimes from his mother's boyfriend, the boy's idol who also is a heroin dealer, and sometimes from other addicts who frequent the family's Southeast Washington home.

The family, which agreed to be interviewed only if their true identities could remain anonymous, did not frown upon drug use. The boy said he some day wanted to sell drugs. One scene in the story described the boy being injected with heroin by the his mother's boyfriend.

Police began searching for the child shortly after the story was published. The Washington Post, citing the need to protect the newspaper's ability to report such stories, refused to identify the youth or give his address to police.

At one point, police threatened to subpoena Janet Cooke, the reporter who wrote the story, to obtain the information, but abandoned that threat after discussions with Charles F.C. Ruff, the U.S. attorney here.

The search for the youth, and heroin abuse in Washington, which some believe to be at near epidemic levels, has dominated discussions on radio talk shows and conversation throughout most parts of the city, in black as well as white communities.

Telephone calls to several local radio shows yesterday indicated that concern has broadened from the little boy and a once anticipated legal battle overpolice threats to subpoena Janet Cooke, the reporter who wrote the story, to the wider problem of heroin addiction, especially among juveniles.

Jerry Phillips of station WHUR-FM devoted an hour of his "Morning Sound" show to discussion of the article and its aftermath. "Sunday and yesterday," Phillips said, "callers were expressing a lot of animosity about The Post for running the story and then not cooperating with the police to find the child. Now, they're not so concerned about The Post, but about what's being done about dope and children.

"One mother called me and said, 'I wouldn't even know if my kid had dope.' The poor folks who call in say they're afraid of the junkies on the street and the professional types are more concerned with plans for doing something to stop this.

"A teacher from Draper Elementary School called and said the corner store there was selling dope. There's a widespread belief that this kind of thing is going on all over the city."

A group of inmates at Lorton Reformatory telephoned The Post and complained that the story was a sensationalized account of a child caught in "the system," but that "what you all ought to be doing is finding out what causes kids like that to get caught in the system and end up doing time like us."

Audrey Rowe, acting commissioner of social services in the Department of Human Services, said that she and other city officials are afraid that if not found soon, the child could die of a heroin overdose of from a dosage that had been adulterated with a foreign substance. Drug experts have noted that the heroin now being sold on D.C. streets was of unprecedented purity and strength.

"You've got to bear in mind that the family has to depend on some outside source for their heroin supply," Rowe said. "Now, those suppliers are not going to be happy about the prospect of the mother and child being taken into custody and the trail then leading to the suppliers. This makes me worry that they could easily adulterate it with something and kill the family -- if they're that cold-hearted."

Police and city social workers continued to ask persons with any information on the child to call one of the two telephone hotlines, one of which was incorrectly reported in yesterday's editions of The Post, due to a typographical error. The correct numbers are 727-0995 and 393-2222.