(AP) Federal prosecutors exaggerated their success convicting would-be terrorists last year by wrongly classifying three of four cases as "international terrorism," a government watchdog says.

Overall, almost half of 288 convictions deemed "terrorism-related" were found by investigators to have been wrongly classified as such for the fiscal year that ended Sept. 30, the General Accounting Office found.

The Department of Justice "does not have sufficient management oversight and internal controls in place to ensure the accuracy and reliability of terrorism-related conviction statistics included in its annual performance reports," reported Congress' nonpartisan watchdog agency.

The GAO report, inspired by a December 2001 article in the Philadelphia Inquirer, sheds light on the effect of public pressure on the department to crack down on terrorism after the Sept. 11 terrorist attacks.

Law enforcement officials, from Attorney General John Ashcroft to the FBI and federal prosecutors, declared that preventing future attacks would be a priority for the department — a new mission that would require millions more federal dollars.

The GAO report said the inaccuracies hampered "the Congress' ability to accurately assess terrorism-related performance outcomes of the U.S. criminal justice system" — information that would be crucial to such congressional endeavors as approving the agency's budget requests.

The GAO said the Justice Department and the prosecutors who report to it have since enacted a series of changes to correct the figures and ensure that future annual reports would be accurate.

The watchdog agency said the discrepancies were due in part to different definitions of terror-related cases used by the agency and the federal prosecutors whose data are included in the agency's annual performance report.

The Justice Department, for example, typically has reported more terrorism-related convictions than the prosecutors because it included convictions obtained in international, federal and state courts, the GAO said.

In contrast, the U.S. attorneys only included federal convictions, the report said.

But the statistics related to both groups were overstated nonetheless, particularly after the Sept. 11 attacks, the GAO found.

In five years before the tragedy reshaped law enforcement's mission, there were an average of 35 terrorism convictions reported annually. In the year afterward, the report said, prosecutors reported 160 terror convictions.

In total, the prosecutors wrongly classified at least 132 of 288 convictions — 46 percent - as terrorism-related for fiscal 2002, the GAO said. All but five of the misclassified convictions were reclassified as anti-terrorism-related, and five were reassigned as other types of crimes.

The prosecutors blamed the discrepancies to "limited time afforded" their staffs to correctly evaluate the data.

One category of the reported terrorism convictions, "international terrorism," was particularly misreported. Of 174 convictions originally classified under that category, only 43 were verified as such — a change of 75 percent, the GAO said.