The three-member board that supervises the U.S. Capitol Police criticized a congressional report yesterday that had alleged Capitol police officers mishandled an investigation into illegal drug use.

The Capitol Police Board said in a statement released yesterday that the earlier report, prepared for the House ethics committee by Joseph A. Califano Jr., "rendered a disservice" to the police by accentuating what the board considered petty problems on the force.

Califano's report, released on May 18, said that the Capitol police failed to follow up on "significant leads" that congressional employes and Capitol police officers themselves may have been buying or selling marijuana, cocaine and PCP in 1980. Calling the failure to fully investigate those leads "inexcusable," the Califano report said that the Capitol Police Board should consider giving responsibility for criminal investigations on the Hill to other law enforcement agencies.

In its report, the board said yesterday that the police pursued all leads into illegal drug use and that the U.S. Attorney's Office here, not police officials, ordered the investigation ended.

Before it ended, that investigation resulted in the arrest of 10 congressional secretaries and maintenance workers on drug charges. One case was dropped, but the other nine resulted in conviction or diversion to drug programs.

The board, comprising Senate Sergeant at Arms Howard S. Liebengood, House Sergeant at Arms Jack Russ and Capitol Architect George M. White, found that Capitol police officials had not destroyed police records relevant to the investigation. Califano had reported that the testimony of some officers before the ethics committee conflicted on that subject.

The board acknowledged that in 1980 the Capitol police lacked detectives trained in drug investigations. Responding to Califano's findings that a well-known Capitol police officer had compromised the investigation by wearing poor disguises as a priest and construction worker, the board described the investigation as "a somewhat clumsy milestone in the evolution of U.S. Capitol Police activity."

The board said that since the initial drug investigation three years ago, the 1,200-officer force had expanded the use of undercover officers, increased drug training for its officers, and set up a drug investigation unit and an internal affairs branch.

"The board believes we've made great strides in this area since then," Liebengood said in an interview yesterday. "Drugs was one of the investigative areas that was late coming" for the Capitol police.

Liebengood said he was "flabbergasted" in May when Califano released the stinging assessment of the Capitol police, and that Califano's report required a response.

Califano began his investigation into the Capitol police in July 1982, when an officer in the department, Ronald Richardson, told committee officials that he had been uncovering leads on Capitol Hill drug use when he was abruptly reassigned. The ethics committee found no evidence that Richardson's transfer had been designed to derail the investigation.