At least 44 pictures showing Americans abusing detainees in overseas military prisons have been permanently blocked from release in an order signed Friday by Defense Secretary Robert Gates.

The firestorm over these pictures erupted earlier this year when the Obama administration decided to comply with and then appeal a court order to disclose the photographs similar to the now infamous pictures from Iraq's Abu Grahib prison.

Under pressure to resist disclosure, President Obama eventually decided to reverse course and appeal the matter to the Supreme Court. Last month, Congress passed legislation--signed into law by Obama--giving the secretary of Defense authority to keep the pictures sealed.

Solicitor General Elena Kagan informed the justices about the Gates directive late Friday.

"I have determined that public disclosure of these photographs would endanger citizens of the United States, members of the United States Armed Forces, or employees of the United States Government deployed outside the United States," Gates said in certifying his decision to keep the photographs under wraps.

Gates said his decision followed the recommendation of Joint Chiefs Chairman Adm. Michael Mullen, Gen. David Petraeus, head of U.S. Central Command and Gen. Ray Odierno, the top U.S. commander in Iraq.

Last year, the New York-based Second Circuit U.S. Court of Appeals ruled in favor of the American Civil Liberties Union's Freedom of Information Act request to force open the pictures. In a statement released Saturday, a top ACLU official expressed disappointment over Gates' decision.

"These photos are an important part of the historical record and they are crucial to the ongoing debate about accountability," said Jameel Jaffer, director of the ACLU National Security Project. "In withholding the photos, Secretary Gates has cited national security concerns, but no democracy has ever been made stronger by suppressing information about its own misconduct."

The high court is now expected to remand the case back to the Second Circuit with orders that it follow the new law and Gate's decision to keep the pictures sealed.