FORT MEADE, Maryland (AP) — The lead attorney for the self-proclaimed mastermind of the 9/11 terror attacks said yesterday he might withdraw from the case unless the judge orders the Government to divulge details about FBI investigations of defence team members.

Civilian defence attorney David Nevin said during a pre-trial hearing in Guantanamo Bay, Cuba, that the possibility that defence team members are working with the FBI has strained his relationship with client Khalid Sheikh Mohammed of Kuwait. The proceedings are video streamed to a room at Fort Meade for journalists.

“It is an extremely extraordinary and singular thing that the FBI tried to invade my defence camp, and it’s astonishing to me and I have no idea why they did it,” Nevin said.

He asked the US Military Commissions judge, Army Col James Pohl, to reconsider his July 24 ruling that the FBI’s actions posed no potential conflict of interest in Mohammed’s case. The ruling was based partly on a special review team’s finding that the FBI was no longer investigating anyone.

Pohl said his order will remain in effect through another pre-trial hearing Oct 13-17 for the five Guantanamo detainees accused of plotting 9/11 in 2001. Teams hijacked and crashed four commercial jetliners, one each into the twin towers at the World Trade Centre in New York City, the Pentagon outside Washington and a field in western Pennsylvania, killing 2,976 people.

Kevin Driscoll, a federal prosecutor on the special review team, discounted Nevin’s speculation about an FBI mole among defence team support staff.

Driscoll said the review team had conducted “extensive searches of FBI holdings”. He assured the judge, “There is no FBI investigation of defence team members, and there is no poison pill or mole in the defence team.”

Little is publicly known about the two reviews. Lawyers say the FBI questioned an investigator and a classified material analyst for the team representing defendant Ramzi Binalshibh; an investigator for defendant Mustafa al-Hawsawi; and a translator on the team representing Mohammed.

Pohl couldn’t rule out a conflict of interest in Binalshibh’s case. Al-Hawsawi’s lawyers have said they don’t believe they have any conflict in continuing to represent him.