DENVER -- A Denver federal grand jury formally indicted the father of an Aurora terror suspect Thursday for making a false statement about international and domestic terrorism, authorities said.

Mohammed Zazi, 53, also of Aurora, was arrested Sept. 19 by the FBI along with his son, Najibullah Zazi, and Ahmad Wais Afzali, 37, a Queens, N.Y., Muslim cleric who authorities captured in phone intercepts allegedly warning the father and son that New York police had questioned him about the younger Zazi.

All three were charged with allegedly making false statements to authorities.

The indictment formally charges Mohammed Zazi with willfully lying when the FBI asked if he "spoke with anyone by telephone regarding whether Najibullah Zazi was in any trouble."

But while the elder Zazi allegedly denied any having such conversation or even knowing the New York cleric, the FBI had secretly recorded the father and Afzali having a 20-minute conversation about his son on Sept 11, according to court records.

Najibullah Zazi had driven from Colorado to New York on the anniversary of the 2001 terror attacks and he met with several men there.

Later, the anxious father called his son to say he would receive a phone call from Afzali, whom the father described as "the imam ... in New York," according to transcripts of the call in court records.

"So before you do anyting else speak with (the imam)," the elder Zazi urged.

"See if you need to go to (the imam) or ... to make yourself aware, hire an attorney," the father warned. He later demanded, "What has happened? What have you guys done?"

When Afzali and the younger Zazi finally talked, the imam tipped the 24-year-old airport shuttle driver that New York police had been asking about him, the FBI said.

"Don't get involved in Afghanistan garbage, in Iraq garbage," Afzali advised Najibullah Zazi during the phone call, according to court records.

Mohammed Zazi is currently free on a $50,000 unsecured bond in Colorado with the condition that he be under electronic monitoring by the court.

He is scheduled to appear in U.S. District Court in Denver at 1:30 p.m. Friday.

If convicted of the charge, Mohammed Zazi faces a maximum of eight years in federal prison and a $250,000 fine.