Attorney General Griffin B. Bell told reporters and Justice Department employees yesterday that he is very disturbed by attmepts to "try cases in the newspapers" through leaks of confidential information from grand jury investigations.

At a news conference, Bell said that, since coming to the Justice Department on Jan. 26, he has seen a large number of "inaccurate press reports" about federal grand jury probes.

He specifically citied stories about separate investigations into allegations tht South Korean officials attempted to bribe members of Congress and that Richard C. Helms, former director of the Central Intelligence Agency, made false statements about CIA activities in Chile.

"I'm not faulting the press," he said. "You have your responsibilities. If I were a member of the media and somebody told me something, I'd print it."

But, Bell added, "I don't think grand jury information should be leaked. Oftentimes it is inaccurate. It doesn't give the full picture. It is a denial of due process."

Citing the Korean investigation as an example, he said that, over a period of a few days, he had seen five different published versions of how many persons allegedly would be indicted. The stories, he charged, ranged widely in the numbers they citied and were all inaccurate.

Within the Justice Department, Bell contended, there are only about 10 people "who know the whole story" of the Korean probe. But, he added, there are about 40 others who know "little parts of it." It was obvious, he said, that the leaks were coming from persons in this group of 40.

As a result, Bell said, "not a single accurate story has been published."

He also cited as "totally false" a recent report by a Wilmington, Del., newspaper that the Justice Department had decided to seek indictment of Helms. Bell reiterated frequent department assertions that the case is still under investigation and that no decisions have been made.

Bell told the press conference that he was going to discuss leaks in an afternoon speech to department personnel. He added: "I'm going to tell them that if they feel they have a right to leak, I at least want it to be accurate. The rights of people are involved."

In the actual speech though, he dropped the irony and delivered a sober warning that "If is essential for all department employees to adhere to strict ethical standards. That means no case, civil or criminal, is to be tried in the press."

Bell reminded his audience that federal laws and rules prohibit "saying or doing anything" that could affect the outcome of a trial. "There is never any excuse for prejudicing the rights of parties to litigation. All of us should know better than anybody else that nothing so harms justice than the transgressions of those sworn to uphold the law," he said.

Bell said that even some of the Justice Department's news releases have amounted to improper interference in pending cases. Although he said he didn't plan to halt the issuance of press releases about indictments, he added:

"One of the biggest complaints of lawyers is that the Justice Department, as soon as it files a suit, it files a press release. If a lawyer did the same thing, he would be disbarred."

In reply to another news conference question, Bell said that within the next week he plans to name a team from the FBI to study whether the Drug Enforcement Administration, which directs the federal narcolics suppression program, should be brought under the FBI's control.

He said the aim would be to determine whether making DEA "a unit under FBI management" would improve the effectiveness of the campaign against illegal drugs.