Washington ? The Justice Department said Thursday it is investigating whether Attorney General Alberto Gonzales lied or otherwise misled Congress last month in sworn testimony about the Bush administration’s domestic terrorist spying program.

Details of the inquiry by Justice Department Inspector General Glenn A. Fine were released three days after Gonzales abruptly announced he was stepping down despite months of vowing to remain on the job.

In a letter to Senate Judiciary Chairman Patrick Leahy, who two weeks ago asked for the inquiry, Fine said his investigators believe they “will be able to assess most of the issues that you raise in your letter.”

Leahy had asked Fine to look into whether Gonzales gave inaccurate testimony about the firings of several U.S. attorneys last year.

“You identified five issues and asked that we investigate whether the statements made by the attorney general were intentionally false, misleading, or inappropriate,” Fine wrote in his four-paragraph response to Leahy dated Thursday.

“The OIG has ongoing investigations that relate to most of the subjects addressed by the attorney general’s testimony that you identified,” Fine told Leahy.

Spokesmen for Gonzales had no immediate comment.

Senate and House lawmakers have said they will continue congressional investigations of Gonzales’ leadership and management at the Justice Department, despite the attorney general’s announcement Monday that he has resigned, effective Sept. 17.

Gonzales’ resignation left the White House scrambling to find a replacement. So far, no single candidate has emerged from a list of more than two dozen lawyers, judges, GOP politicians and current and former Justice Department officials being discussed.

White House spokeswoman Dana Perino said Thursday it was unlikely that Gonzales’ successor will be named until President Bush returns Sept. 9 from the annual Asia-Pacific Economic Cooperation forum in Australia.

Gonzales announced his departure a month after his truthfulness was challenged during a Senate Judiciary Committee hearing. At the bitter hearing, Gonzales denied that he tried in 2004, as White House counsel, to push the Justice Department into approving the administration’s Terrorist Surveillance Program – despite concerns that it was illegal.