A man accused of planning the September 11 attacks on the United States is expected to be formally charged on Sunday (NZ time) before a military tribunal at Guantanamo Bay.
It will be the second attempt to try Khalid Sheikh Mohammed and four other men by military tribunal, the BBC reports.
During the first trial, Mohammed said he intended to plead guilty but the case was halted by the election of President Barack Obama who wanted to transfer the Guantanamo Bay trials to civilian courts.
But the chief prosecutor, Brigadier General Mark Martins, says there are good reasons why some cases should be tried in military courts.
New rules for Guantanamo trials have been introduced, including a ban on evidence obtained under torture.
Waterboarded 183 times
Khalid Sheikh Mohammed has alleged that he was repeatedly tortured during his detention in Cuba.
CIA documents confirm that he was subjected to simulated drowning, known as waterboarding, 183 times.
Defence lawyers still say the system lacks legitimacy, because of restricted access to their clients.
President Obama's efforts to hold Khalid Sheikh Mohammed's trial in New York foundered in the face of political and public opposition and it will now be held at a military tribunal in Guantanamo Bay, as previously planned.
Self-proclaimed 9/11 "mastermind" Khalid Sheikh Mohammed and the four others - Waleed bin Attash, Ramzi Binalshibh, Ali Abd al-Aziz Ali and Mustafa Ahmad al-Hawsawi - are expected to be tried together.
They are accused of planning and executing the terror attacks of 11 September 2001, which saw hijacked planes strike New York, Washington and Shanksville, Pennsylvania and left a total of 2,976 people dead.
At the arraignment, they will be read charges including terrorism, hijacking, conspiracy, murder and destruction of property.
They are expected to be asked to enter a plea for the first time.
Jim Harrington, the civilian lawyer for Ramzi Binalshibh, told Associated Press that although his client had previously said he was "proud" of his role in the attacks he had "no intention of pleading guilty".
"I don't think anyone is going to plead guilty," he added.
The Pentagon has previously said Khalid Sheikh Mohammed, who is of Pakistani origin but was born in Kuwait, admitted he was responsible "from A to Z" for the 9/11 attacks.
In a previous court hearing he has said that he intended to plead guilty and would welcome martyrdom.
He was captured in Pakistan in March 2003 and has been detained at Guantanamo Bay since 2006.
US prosecutors allege that he was involved with a host of other terrorist activities.