The Justice Department has found no incidents in which the anti-terrorism Patriot Act has been invoked to abuse civil rights or civil liberties but has identified instances of mistreatment of Muslims and Arabs that did not involve the act.

Tuesday's report probably will provide fodder for Bush administration efforts to persuade Congress to renew the law, which expires in 2005. The law, passed shortly after the Sept. 11 terror attacks, faces a legion of critics who contend its expansion of government surveillance powers violates constitutional free speech and privacy rights.

"It is clear that the government has been thoroughly responsible in its implementation of the act," said Justice Department spokesman Mark Corallo. "As the president has said, it is vital that Congress reauthorize these provisions."

But Rep. John Conyers, senior Democrat on the House Judiciary Committee whose Michigan district includes many people of Arab descent, said the report failed to identify "a single punishment or sanction" imposed on a Justice Department employee found to have violated civil rights and civil liberties.

He said Attorney General John Ashcroft "needs to get the department's house in order if we are to have any credibility in pursuing the war against terror."

Under the Patriot Act, the Justice Department's inspector general is required to investigate allegations of civil rights and civil liberties abuses directed against Muslims, Arabs and others in the aftermath of the Sept. 11, 2001, terror attacks blamed on Islamic extremists.

The new report by Glenn A. Fine, the Justice Department's inspector general, found that 1,266 civil rights and civil liberties complaints were received between June 15 and Dec. 15, 2003. Of those, only 17 involved Justice employees and merited a full investigation.

Most involved allegations of excessive force, verbal abuse and other alleged mistreatment at Bureau of Prisons facilities.

The report found no civil rights or civil liberties abuses specifically related to the Patriot Act, which authorized more phone wiretaps, expanded government search powers and enhanced other surveillance techniques.

House Judiciary Committee Chairman James Sensenbrenner, R-Wis., said that finding should undercut "those who are intent on skewering the Patriot Act with misinformation."

In all, the inspector general checked 162 complaints involving Justice employees. Another 384 were against other federal agencies or state and local government entities and were referred to those agencies for investigation.

Among the cases that were closed:

--An unidentified immigration agent improperly displayed his credentials to an Arab-American gas station attendant who said he was out of paper towels that the agent wanted. The agent also demanded the attendant's immigration documents and improperly checked government databases for information about him.

--A Bureau of Prisons guard acknowledged that he had previously misled investigators and now acknowledged verbally abusing a Muslim inmate and throwing his Quran into a garbage can.

--Investigators could not substantiate another inmate's claim that an immigration enforcement officer held a loaded gun to the inmate's head and threatened him while he was being transported.

--An Arab-American man who complained that Drug Enforcement Administration agents illegally searched his home and confiscated passports and personal property was charged in connection with a drug probe and is now a fugitive. The report found no wrongdoing by the DEA.

Several other complaints remain under investigation, including one from a federal prisoner who claimed that a prison warden and some guards threatened to gas certain inmates after the Sept. 11 attacks. An Egyptian man detained after the attacks said he was improperly forced to undergo a body cavity search in the presence of numerous people, including a woman.

Most of the complaints -- 720 -- were found to be unrelated to civil liberties or civil rights. These included claims that the government is broadcasting harmful signals to people or that its agents are intercepting their dreams, according to the report.