Updated

An FBI agent has started describing the case against a Saudi citizen accused in the Sept. 11 attack for the first time since the prisoner was arraigned on capital charges at the Guantanamo Bay detention center more than six years ago.

Special agent James Fitzgerald took the witness stand at the U.S. base in Cuba as prosecutors challenge a motion to dismiss charges against Mustafa Ahmed al-Hawsawi.

Fitzgerald began the hearing Tuesday by detailing the FBI investigation into the terrorist attack of Sept. 11, 2001. Al-Hawsawi faces charges that include terrorism and murder for providing financial and logistical support.

The 49-year-old Saudi and four others held at Guantanamo were arraigned in May 2011. The complex case remains in the pre-trial stage and no trial date has been set.