An influential Muslim cleric, instrumental in reaching out to law enforcement after the Sept. 11 terror attacks, arrived at a federal immigration courthouse in Newark, N.J., Thursday to fight deportation.

Imam Mohammad Qatanani, accompanied by his wife and six children, had little to say as he walked past several hundred supporters holding signs and American flags on his way to court.

The imam, who is expected to take the stand in his defense, prayed with his attorney inside the courthouse before the hearing got underway.

Qatanani has been in the U.S. since 1996 and heads the Islamic Center of Passaic County. The imam is well known for working with the FBI following the 9/11 terrorist attacks and for calling on his followers to do the same, although supporters say he worked with law enforcement long before 9/11.

Immigration authorities want to deport him because he didn't disclose a prior conviction in an Israeli military court when he applied for U.S. citizenship more than a decade ago.

The first witness for the prosecution was a former Israel military judge who testified that Qatanani was arrested for belonging to and supporting Hamas, a group the U.S. declared a terrorist organization in 1995. The witness said that Qatanani agreed to plead guilty in 1993.

During the hearing, which is expected to continue through Monday, the imam is expected to admit he was detained, but will likely testify he was never given proper trial and was released from Israeli custody after three months.

Qatanani has previously denied belonging to Hamas, and supporters say he has consistently denounced Hamas and all terrorist organizations.

He has received support not only from his Islamic Center of Passaic County, but also from Jewish and Christian leaders who have worked alongside hime, some of whom are expected to testify on his behalf. Supporters have raised $100,000 and pledged to protest every day of the hearing.

A federal immigration judge could rule as early as Monday whether Qatanani will be deported or given another chance at residency. If the judge rules against him, he can appeal, and the case could go all the way to the Supreme Court.

Any ruling will also affect his wife and six children, three of whom were born in the United States.

The Associated Press contributed to this report.