The lawyer representing the alleged mastermind of the 9/11 attacks has hit out at the US government for preventing him from speaking to his client.
David Nevin's criticism came on Sunday a day after a 13-hour marathon session in which Khalid Sheikh Mohammed, his client, and four co-defendants appeared before a military judge at the US naval base in Guantanamo Bay, Cuba.
Al Jazeera's Rosiland Jordan, reporting from Guantanamo, said the message from all the lawyers is that the military commission under which the men are being tried is "tainted beyond repair".
Our correspondent said Nevin said he would "use every trick he can find under the rubric of the US constitution" to ensure his client got a fair trial.
In an interview with Al Jazeera, Nevin said the US government was "trying to prevent the world from knowing that his client was actually tortured for three years".
"One of the problems I have is that I can't tell you what my client has said to me; I can't tell you what he is thinking because I am forbidden from doing that," Nevin said.
"Everything he says is presumptively classified at the top secret level. No one ever told me whether that's necessary or that's appropriate.
"That the ideas, the observations, in a man's head can somehow be classified information. That's absurd. This has never been the case in the history of the United States."
The accused face charges that include terrorism and 2,976 counts of murder for their alleged roles planning and aiding the attacks by hijackers aboard four airliners.
The attacks, which left at least 3,000 people dead, destroyed the World Trade Center in New York and damaged the US defence department headquarters at the Pentagon, near Washington DC.
In addition to Mohammed, a Kuwait-born Pakistani who was captured in 2003 and transferred to Guantanamo in 2006, four other men face trial over their alleged roles in the 2001 attacks.
They are Waleed bin Attash, Ramzi Binalshibh, Ali Abd al-Aziz Ali and Mustafa Ahmad al-Hawsawi. All five men could face the death penalty if convicted.
Saturday's session got off to a rocky start, with the defendants removing their earphones and refusing to answer questions from the judge as to whether they accepted to be tried by the tribunal.
It was not until more than seven hours into the disrupted and prolonged hearing that prosecutors even began reading the charges against the men.
It took prosecutors two-and-a-half hours to read the portion of the charge-sheet describing the hijackings, although they did not read the appendix listing the names of all 2,976 people who were killed.
Another hearing has been set for June 12.