A federal appeals court ruled Friday that a former college professor and Palestinian Arab activist, Sami Al-Arian, did not have the right to defy a subpoena from a federal grand jury in Virginia.

The 11th Circuit Court of Appeals rejected Al-Arian’s arguments that his 2006 agreement to plead guilty to one felony count of aiding Palestinian Islamic Jihad included a promise that he would not have to cooperate with other federal investigations.

“Al-Arian’s plea agreement contains no mention of whether he could be compelled to testify before a grand jury in the future. It also contains an integration clause, providing that the plea agreement reflects all of the promises and agreements between Al-Arian and the government,” Judges Stanley Birch Jr., Rosemary Barkett, and Edward Korman wrote. “We cannot conclude that Al-Arian reasonably believed that he would forever be immune from all grand jury subpoenas originating from any federal prosecutor’s office.”

Al-Arian spent about a year in jail for refusing to testify in a probe of Islamic charities in Virginia. The contempt citation was dropped last month, but Al-Arian still has a few months to serve on the terror-support charge and could also face a criminal prosecution for his defiance of the grand jury.