The Justice Department announced yesterday that it has ended its probe into allegations of sexual misconduct on Capitol Hill because there is insufficient evidence to warrant federal prosecution or further investigation.

Federal officials are continuing their investigation into allegations of illegal drug use by members or employes of Congress, according to a Justice Department spokesman.

Sources have said the department believes it is too early to reach a conclusion about those drug allegations, which include charges that a cocaine distribution ring operated on Capitol Hill.

In a brief statement yesterday on the decision to shut down the sex-related investigation, Associate Attorney General Rudolph Giuliani said the Justice Department's criminal division had reviewed all allegations "about the conduct of certain Capitol Hill pages and others" and determined that the evidence was insufficient.

"The matter is now closed," Giuliani said.

The department's decision does not affect an independent investigation now being conducted by veteran Washington lawyer Joseph A. Califano Jr., who is acting as special counsel to the House Ethics committee.

The committee could recommend that the House take administrative action against members or employes in connection with either the sexual misconduct or drug abuse allegations.

Former Capitol Hill page Leroy Williams, whose public allegations about sexual misconduct on Capitol Hill touched off a public furor, confessed last week that he manufactured his story to bring attention to what he viewed as problems in the page system. Williams appeared before the ethics committee in a closed session last Saturday and affirmed -- this time under oath -- that his charges were lies.

Afterward, House ethics committee Chairman Louis Stokes (D-Ohio) said that despite Williams' admission, the committee would continue its investigation. At least two other former pages have made allegations of sexual misconduct.

Giuliani said in his statement that the department intends to cooperate fully with committee investigators.

Justice Department spokesman Arthur Brill said the department has "no plans at this time" to bring criminal charges against Williams.

A special House commission recently recommended tighter supervision of the page system, in which teen-agers are hired to run errands for members of Congress.