Miami ? Federal prosecutors on Friday released an application to join an al-Qaida training camp in Afghanistan purportedly filled out by accused terror operative Jose Padilla.

The “Mujahideen Data Form” bears the signature of Abu Abdallah al Muhajir, which the FBI says is the Muslim name that Padilla adopted after he converted to Islam.

Defense attorneys have questioned the authenticity of the document, potentially a critical piece of evidence for prosecutors attempting to prove that Padilla sought to become a terrorist.

Federal prosecutor Stephanie Pell has said Padilla completed the form to begin training in Afghanistan in July 2000. She said it was found by U.S. forces in late 2001 in a binder that contained other terror camp applications.

Padilla is accused of being part of a North American terror support cell that provided material, money and fighters for Muslim extremist causes. He has pleaded not guilty.

“He was recruited to travel overseas to engage in jihad or armed confrontation,” Pell said at a hearing Thursday. The form was released after prosecutors filed it with the court.

Padilla, a U.S. citizen, was charged in November after more than three years in military custody as an “enemy combatant.” U.S. officials have said he was plotting to detonate a radioactive “dirty bomb” or blow up apartment buildings in an American city, but those allegations are not part of the criminal case expected to go to trial in September.

One of Padilla’s attorneys, Michael Caruso, said at the hearing Thursday there is scant evidence to link Padilla to the form and insufficient proof that it is authentic.

“Weak is not the right word,” Caruso said of the government’s case.

The form, translated from Arabic by the FBI, contains questions about education, languages spoken and marital status. It also asks about religious training and whether the applicant has military experience.

In an answer to one question, Padilla allegedly said that he traveled to “Egypt, to study – Saudi Arabia for Hajj (the Islamic religious pilgrimage) – Yemen, as a way to go through for Jihad.”