A House subcommittee plans to investigate long-dormant charges that Attorney General Griffin B. Bell undermined his own Justice Department probe of illegal break-ins by FBI agents.

The announcement of the new inquiry, which probably won't result in public hearings before next year, is buried in a report to be released today by a Government Operations subcommittee headed by Rep. Richardson Preyor (D.-N.C.).

The charges by members of the original Justice task force in the FBI case created a one-day sensation at a Senate hearing in April. But unitl now no one has expressed interest in following up what the House report says are "serious questions about the department's handling of the case."

Preyor could not be reached for comment yesterday. But a subcommittee aide said members decided to hold up a public inquiry to avoid prejudicing cases against the three former top FBI officials indicated in the case in April. Gathering documents and interviewing principals may begin soon, however, he added.

The dispute between Bell and attorneys on the initial task force centered on the attorney general's refusal to follow recommendations that eight FBI officials be indicated. Four of the five Justice lawyers involved quit the case last December as a result.

"It is vital that any lessons to be learned from its (the FBI case) handling not be lost for failure to look back at what happened in the investigative and decision-making process and document why it happened," the subcommittee report said.

The report also touches on the FBI break-ins case in making recommendations about the Justice Department's "internal investigation policies."

The department's internal investigative arm, the office of professional responsibility, plays a sensitve role at Justice because of allegations of foot-dragging by department officials in the Watergate scandal.

Administrative action should not be held up until officials under criminal investigation are charged or cleared, the report said. FBI Director William H. Webster is still considering disciplinary action against 68 FBI agents who took part in the allegedly illegal break-ins.

The report also suggested that officials might be placed on paid leave during investigations, rather than being in limbo in powerful positions, as J. Wallace LaPrade was during the break-ins inquiry.

LaPrade, head of the FBI's New York office, was fired by Bell last month for allegedly lying to prosecutors in the case. Bell rejected their recommendation that the high-ranking FBI official be indicated for perjury. LaPrade is appealing his dismissal.

The subcommittee report also recommends that an outside group, rather than the office of professional responsbility, investigate allegations against the attorney general.

Citing the office's investigation of Bell's controversial firing of Philadelphia U.S. attorney David W. Marston, the report said: "The entire exercise was futile and damaging to OPR's credibility." It appeared to skeptics that Bell had used the internal investigating arm to clear himself, the report said.

Republican Marston was dismissed amid reports that he was investigating two Democratic House members, which set off charges that the attorney general obstructed justice.

To ensure the independence of the office, the report recommends setting up OPR by law, rather than by department regulation.