NEWARK, New Jersey: Federal immigration officials are appealing the case of a New Jersey Muslim leader who won his fight to remain in the United States, a move the leader's spokesman said may damage hard-won trust between Muslims and law enforcement.

U.S. Immigration and Customs Enforcement wants the Board of Immigration Appeals to review the decision to stop the deportation of Mohammad Qatanani, a Palestinian leader accused by some federal officials of having terrorist ties but praised by others as being an important ally.

Qatanani, 44, won his fight to gain permanent U.S. residency in September, when a federal immigration judge determined the government's case against him was too weak to prove he had any ties to extremist groups.

The ruling would allow Qatanani and his family to remain in the country and eventually be eligible to apply for citizenship.

Immigration authorities had sought to deport Qatanani on grounds that he failed to disclose on his residency application an alleged prior arrest and conviction in Israel for being a member of Hamas � a group classified as a terrorist organization by the U.S. government.

Qatanani has denied being a Hamas member and said he was detained, not arrested, by the Israelis while traveling to his native West Bank in 1993.

Immigration Judge Alberto J. Riefkohl questioned the reliability of the records submitted by the Department of Homeland Security purporting to show Qatanani's arrest and conviction in Israel. The judge called the U.S. government's case against Qatanani "patently incomplete," and found its two key witnesses � both federal agents � to not be credible.

ICE spokesman Harold Ort said the agency questions the judge's decision to allow Qatanani to stay.

"ICE believes that the immigration judge made mistakes of law, judgment and discretion," Ort said. He declined to elaborate further or provide a copy of the appeal.

Qatanani has received support from U.S. law enforcement officials, including U.S. Attorney Christopher Christie.

The 44-year-old Palestinian has served as the imam, or Muslim religious leader, since 1996 at the mosque in Paterson, a city that is home to one of the region's largest Muslim populations.

Qatanani supporters said the government's decision to appeal was being seen as more than just a procedural court filing.

"We hoped they wouldn't pursue this case, as a gesture of good will, and because of the important need to reconnect with our community and build trust again," said Aref Assaf, a member of the group Americans 4 Qatanani, which supported the imam's immigration fight. "It seems that there has been a political decision at a higher level to pursue this case, and they continue to persecute � not just prosecute � our community and our leader."

Assaf said word of the appeal was spreading quickly to mosque members.

"We thought it was only a case against the imam," Assaf said, "but now we're seeing it as a case against the community and all Muslims."