CNN

WASHINGTON (CNN) - The Justice Department informed a federal court Thursday that it now needs until the end of August to complete its review of a CIA internal investigation of its controversial interrogation and detention program.

In a letter to Judge Alvin Hellerstein, Justice officials said the 2004 Inspector General's report had to be considered in relationship to 318 other documents under court-ordered review.

Justice Department Spokeswoman Tracy Schmaler said some of the information contained in the 2004 report related to information contained in the other CIA documents. "Because of the overlap, we cannot complete the review of the report before the review of this other set of documents," said the spokeswoman.

The court had ordered the review of all of the CIA documents to be completed by August 31, but the government had said it would expedite its consideration of the inspector-general report, setting a deadline of June 19 - a deadline it has extended twice.

In the letter to the court, the Justice attorneys said, "Given the sensitivity of the information at issue, and the need for coordination among multiple components of the government, the review of the remanded documents is a time consuming and labor intensive exercise."

The Justice Department is trying to determine how much of the secret 109-page inspector-general's report can be made public in response to an American Civil Liberties Union lawsuit.

The ACLU fired off a letter to Hellerstein urging him to reject what it called "the government's attempt to delay release of the (inspector-general's) report until August 31." The ACLU called the government's position "flawed," saying release of the inspector-general's report "would aid, not risk inconsistency with... the remaining CIA documents."

The ACLU had sued the government for the public release of all documents related to the CIA's interrogation and detention program. Last year, the CIA released the inspector-general report with most of the 109 pages either withheld or heavily blacked out. The ACLU complained to the court that the CIA was withholding information "not for legitimate security reasons." The Obama administration agreed to review the report to see what more could be released.