The U.S. Capitol Police failed to follow up on "significant leads" into possible drug activity on Capitol Hill in 1980, including allegations of use and sales by lower-level congressional employes and three members of the police force itself, the House ethics committee said yesterday.

"The failure to pursue these leads represented an abdication by the Capitol Police of its responsibility to investigate allegations of serious violations of law within its jurisdiction," a report from committee investigators said. The report was adopted by the committee and released yesterday.

". . . the failure of the Capitol Police officers to pursue allegations of illegal drug activity by its own members is inexcusable," the report concluded.

The ethics committee investigators also found that members of the police force shredded records relating to Capitol Police drug investigations last summer, around the time the team was starting its own probe, but that there is no evidence that the information contained in the records was important.

The leads developed in 1980 included signed statements naming several Hill employes as distributors of marijuana, PCP and cocaine, and some of these employes still work on the Hill, the report said. Witnesses also signed statements that three members of the police force had bought, sold or offered to sell them marijuana.

None of the evidence uncovered in the 1980 investigation implicated any congressmen or House professional staff, the report stated. There was insufficient evidence to conclude that the Capitol Police purposely obstructed the investigation or covered up for members of the force, it said. The report did not deal with the substance of the allegations or say whether the ethics committee investigators have looked into them.

The investigating team, headed by special counsel Joseph A. Califano Jr., was formed last summer by the House ethics committee to look into allegations of sexual misconduct and drug activities on Capitol Hill.

The Califano group's probe into the earlier police investigation, the report said, was sparked by claims last July by a Capitol Police officer that he and a colleague had been close to uncovering evidence of drug activity in 1980 when they were reassigned and the probe allowed to languish.

The Califano report was sent yesterday to the Capitol Police Board, which has authority over the Hill police force. The report said the board and Congress as a whole should review the role of the force and whether it should be responsible for investigating criminal activity. The board, which is composed of the Architect of the Capitol and the House and Senate sergeants at arms, also should decide whether disciplinary action against any of the police officers is warranted, it said.

The Capitol Police force has about 1,200 officers one of the 30 largest in the country and is nearly the size of San Diego's metropolitan police force, the report pointed out. It polices the Capitol buildings and grounds and can make arrests for any violation of federal or District of Columbia law.

One of the original officers conducting the Capitol Police investigation, Sgt. Ronald Richardson, had claimed his transfer to new assignments was part of a coverup, but the report said it was not.

The report quoted several members of the police force as saying Richardson had lost all perspective on the investigation and had become obsessed with it. He disguised himself as a priest, a construction worker and a derelict, using makeup and false beards. His superiors referred to these as "bizarre" and evidence he needed to be reassigned.

Reached for comment at home, Richardson said he had not seen the report and had not known it was going to be released or his name mentioned in it. He declined comment until he could get a copy.