A controversial national police intelligence association, which federal officials tried to merge with the FBI's computer operation three years ago, has had serious leaks of intelligence material to the underworld going back to 1960, according to FBI files.

The files indicate that an official in the Law Enforcement Intelligence Unit, a privately chartered group that received federal funds until this year, apparently took a file on organized came from federal agents during the 1960s. The theft so angered FBI officials that they set up their own intelligence network inside LEIU to report on the group's activities.

According to the FBI files, one LEIU chapter in Colorado leaked data on organized crime to underworld figures in 1960 and two other chapters were tossed out of the group during the 1960's "on corruption charges."

LEIU's most recent leak problem occurred this year when an FBI wiretap uncovered information that an intelligence specialist with the Las Vegas police with access to LEIU files was leaking organized crime material to reputed mobsters. The Las Vegas chapter was thrown out of the LEIU in September.

Despite such intelligence transgressions an adviser to then acting FBI director L. Patrick Gray III recommended in 1972 that the FBI cooperate more closely with the LEIU.

Gray apparently rejected the advice. But the Justice Department's Law Enforcement Assistant Administration, which funded LEIUI's computer operation until June of this year, was still trying to merge the FBI and LEIU computer networks in 1975, citing possible violence during the Bicentennial as a reason for the matchup.

The FBI files were obtained recently by David Power, a Temple University law student, through the Freedom of Information Act.

The LEIU was started in 1956 to exchange organized crime data among local police departments. Officials testified for the group in 1974 before a Senate investigating committee that LEIU files were closely protected and only included data on organized crime.

Recently the association has come under fire from civil rights activists who claim LEIU intelligence files include material on civil rights activists, black organizations, antinuclear groups and others with no organized crime affiliation.

According to the FBI files, the LEIU leaks go back to 1960 when sensitive intelligence material was escaping through the LEIU chapter in the Pueblo, Colo., police department.

Our Dallas office was advised . . . that the LEIU date received by the Pueblo police had in turn, been passed along to the underworld noted a 1972 background memo on the LEIU which was compiled by the FBI.

The memo continued that the LEIU police chapters in Denver and Kansas City were evicted from the organization during the 1960's because they were corrupt.

Maj Steven Bertucell of the Dade County, Fla., public safety department, who is LEIU's general chairman, said yesterday that the group's Las Vegas police chapter - was alos expelled in September of this year on corruption charges, FBI investigators learned through a wiretap in Detroit that intelligence data was being leaked to underworld figures by a Las Vegas police detective who had access to the LEIU computer, Bertucelli said.

He said the FBI did not notify the LEIU of the leak and the group only learned of the security violation through newspaper stories.

But perhaps the most serious security violation, in the eyes of the FBIs memo writers, was the apparent theft by an LEIU official in Texas in 1966 of a Xerox copy of an FBI file entitled "La Cosa Nostra, Anti-Racketeering-Conspiracy."

The LEIU official, identified as a former Dallas police official, got the report "through surreptitious means," according to the FBI. The FBI file does not indicate if the material made its way into underworld hands.

As a result, FBI field offices were instructed to keep close watch on LEIU activities, and the FBI rejected attempts to merge its computerized files with LEIU computers. One FBI memo in 1971 reported that the bureau sources werereporting on a 1971 LEIU meeting in New York. No sentiments or opinions unfriendly to the bureau were expressed, the memo noted.

In another 1972 memo,Daniel M. Aranston III, an administrative aide to acting FBI director Gray, advised Gray to make knownto LEIU your willingness to give [WORD ILLEGIBLE] consideration to specific requests or suggestions from them or improved relationship.

A similar attempt to knit together the intelligence operations of the FBI and the LEIU was made by Justice Department officials in 1975. The FBI memos paint the Justice Department effort as an attempted power grab by the department's LEA using the potential threat of Bicentennial year violence to Justify its interest.

An FBI Spokesman said yesterday that there is no mingling of intelligence data between the FBI and the LEIU. "I don't think we ever got involved with them at all," the spokesman said.