A Justice Department study of the Law Enforcement Assistance Administration concludes there should be a wholesale restructuring of the much-criticized agency, which has poured nearly $6 billion into crime-fighting programs since 1969.

In releasing the report yesterday, Attorney General Griffin B. Bell said he had reached no conclusions on the task force's recommendations to change LEAA by putting more emphasis on research and by funneling money more directly to states and localities while cutting the requirement of detailed plans for spending the funds.

Both Bell and his top deputy, Peter F. Flaherty, have publicly questioned whether LEAA should be continued at all. But sources at Justice and on Capitol Hill agreed yesterday that the agency has too many political friends to be abolished.

One of the seven-member Justice study group said in the report that LEAA should be junked altogether and its funds, about $700 million a year, redirected to other programs. Paul Nejelski, a deputy assistant attorney general, added in a telephone interview that it would be difficult to kill the program because so many "criminal justice professionals" are funded by LEAA grants.

"They've [LEAA] bought themselves a big lobby," he said.

A key congressional staff member predicted yesterday that LEAA would survive any efforts to dismantle it because "it's one of the great pork barrels of all time. It rivals water projects."

The study group's report is couched in such general terms that Bell will have great flexibility in tailoring legislative proposals needed to implement the changes.

For instance, the report makes only passing reference to the basis of the politically-sensitive formula by which LEAA funds are distributed to states and cities. Sen. Edward M. Kennedy (D-Mass.) already has proposed more specific criteria.

One Justice Department official familiar with the task force deliberations said, "It was a necessary part of the process. But Bell and Flaherty's public statements say more about the direction the department really would like to move."