For a third time, a military judge has authorized lawyers for Osama bin Laden's driver to send questions to alleged al Qaeda kingpins in segregation at Guantánamo.

The ruling by Navy Capt. Keith Allred rejected national security arguments raised by Pentagon prosecutors. The military judge also sounded dismissive of a government argument that the driver could have conspired in the Sept. 11, 2001, attacks without knowing about the suicide plot.

Specifically, Allred authorized the lawyers to ask reputed mastermind Khalid Sheik Mohammed whether the driver was a part of the 9/11 suicide plot and other al Qaeda attacks.

'The issue of whether the accused was `merely a driver,' or knew the unlawful purpose and was actively engaged in the unlawful work of al Qaeda seems to be very much at issue,'' Allred wrote in the four-page ruling, dated Friday.

The Pentagon made it public on Wednesday, intact, with no portions blacked out. Earlier judges' rulings have been censored.

It was the latest setback to Pentagon prosecution efforts to limit the discovery phase before the separate military trials of the driver, Salim Ahmed Hamdan of Yemen, and Canadian captive Omar Khadr. Both are slated to face military commissions this summer.

Pentagon prosecutors had three times resisted the judge's plan to let Hamdan's lawyers ask questions of seven former CIA captives. They have been at Guantánamo since September 2006 and are now held as ''Task Force Platinum'' prisoners,at a segregated site set up secretly by the military, called Camp 7.

Under the scheme, devised by Allred, defense lawyers submit questions for Mohammed and the others to an independent security officer who works for the judge, not the prosecution.

The judge limited the substance to the time before Hamdan's capture in November 2001 in Afghanistan, and before the men were held and interrogated secretly by the CIA overseas -- meaning they cannot divulge U.S. interrogation techniques.

The security officer will have the questions translated, as well as the answers -- and then black out any responses that don't cover that time period.

Allred said in his ruling that national security could be safeguarded by the special security review.

Even before the Pentagon made the ruling public, defense lawyers had on Tuesday already submitted written questions for four of the men, chief among them the man known in CIA circles as KSM, Mohammed.

Navy Lt. Cmdr. Brian Mizer, Hamdan's Pentagon appointed defense counsel, called Allred's ruling ``a real rebuke of the government's dragnet theory of conspiracy as well as granting us access to these detainees.''

The questions for Mohammed specifically ask, ''What was Hamdan's involvement in Sept. 11,'' said Mizer.

Based on their research, he said, the answer should be, ``nothing.''

Hamdan, 36, is accused of being a driver and sometime bodyguard for Bin Laden prior to the 9/11 attacks in Afghanistan. He is broadly charged as a co-conspirator in the terror plot and other al Qaeda attacks. Conviction carries life in prison.

Hamdan has admitted that he worked for bin Laden, and earned $200 a month as a driver. But he says he never joined al Qaeda and did not plot any attacks.

Allred wrote: ``It is not unfair to permit the Defense to seek to show that while he may have been a bodyguard and driver, he knew little or nothing about the inner workings of this conspiracy, or that was not a party to it, if they can.''