The FBI found apparent violations of its own wiretapping and other intelligence-gathering procedures more than 100 times in the last two years, and the problems appear to have grown more frequent in some crucial respects, a Justice Department report released on Wednesday said.
While some of these instances were considered technical glitches, the report, from the department's inspector general, characterized others as "significant," including wiretaps that were much broader in scope than approved by a court and others that were allowed to continue for weeks or sometimes even months longer than was authorized.
The inspector general's findings come at a time of fierce congressional debate over the program of wiretapping without warrants that the National Security Agency (NSA) has conducted.
That program, approved by US President George W. Bush, is separate from the FBI wiretaps reviewed in the report, and the inspector general's office concluded that it did not have the jurisdiction to review the legality or operations of the NSA effort.
But, the report disclosed, the Justice Department has opened reviews into two other controversial counterterrorism tactics that the department has widely employed since the Sept. 11, 2001 attacks.
In one, the inspector general has begun looking into the FBI's use of administrative subpoenas, known as national security letters, to demand records and documents without warrants in terror investigations. Some critics maintain that the bureau has abused its subpoena powers to demand records in thousands of cases.
In the other, the Office of Professional Responsibility, a Justice Department unit that reviews ethics charges against department lawyers, has opened inquiries related to the detention of 21 people held as material witnesses in terror investigations.
For its part, the FBI said in a statement that it had been quick to correct errors in intelligence-gathering procedures when they were discovered and that "there have been no examples by the FBI of willful disregard for the law or of court orders."