The Justice Department's internal investigations unit received 468 complaints last year about department employes' alleged wrongdoing, including allegations of bribery, drug use and fraud against the government, according to a report released yesterday.

The Office of Professional Responsibility, headed by Michael Shaheen Jr., also reported that in 1982 it monitored an additional 1,300 investigations by internal watchdog units in various Justice agencies, including the FBI, the Drug Enforcement Administration, the Immigration and Naturalization Service and the Bureau of Prisons.

Among probes detailed in the report were those dealing with:

* A secretary in a U.S. attorney's office, who told superiors that she saw an assistant U.S attorney using drugs at work and elsewhere. The secretary passed a lie-detector test, and the official resigned.

* An INS investigator demoted after allegations that he had destroyed an official vehicle while he was "highly intoxicated." The employe was involved in an accident on official business and then was observed setting fire to the vehicle's seats. When authorities arrived, they found the vehicle on fire and the employe asleep nearby.

* A Border Patrol agent, arrested by local authorities for shoplifting and theft, fired after it was discovered that he had been calling in sick while under arrest.

* Two Border Patrol agents charged with violating the civil rights of two woman aliens near the Mexican border by forcing them to have sex with them. The agents, who forged records in an attempt to clear themselves, were convicted and sentenced to jail for criminal civil-rights violations, obstruction of justice and attempting to use forged records at a criminal proceeding.

The Shaheen report, the seventh annual one from his office, said 46 percent of the complaints involved criminal acts, including bribery, obstruction of justice, conflict of interest, drug use and fraud.

Among other complaints, 32 percent involved abuse of prosecutorial or investigative authority or mistreatment of inmates, 11 percent involved unauthorized release of official information and 11 percent involved such miscellaneous allegations as prohibited political activity or personnel processes.

The number of complaints to Shaheen's office increased about 18 percent since the 1981 report.

Cases outlined in the report did not identify employes or complainants. In other examples:

* An undercover FBI agent was arrested for felony shoplifting at a local department store and attempted to conceal his identity by using his undercover name and identification cards. He was fired and ordered to perform 160 hours of community service.

* A federal prison employe pleaded guilty to bribery charges after an inmate charged that the employe was soliciting payment in exchange for letting inmates accompany him on trips outside the prison. After the inmate was told that, for $250, he could spend a few hours with his girlfriend at a local hotel, an FBI agent posed as the girlfriend and paid the $250 while the proceeding was recorded.

* A DEA agent was investigated after an ex-informer said the agent was selling her drugs and was sexually involved with her. When videotaped surveillance and an investigation backed up the allegations, the agent resigned, later pleading guilty to distributing drugs. He received a five-year sentence.