TAMPA — A former University of South Florida professor accused of aiding terrorists has been deported to Turkey, ending more than a decade of controversial litigation that first landed in the national spotlight amid growing tensions between civil liberties and national security.

The federal government's prosecution of Sami Al-Arian even turned into a political issue during the 2004 U.S. Senate campaign, with the two candidates trading barbs about which of them had closer ties to the professor.

Al-Arian, 57, and his wife, Nahla, boarded a commercial flight out of Washington on Wednesday night, said U.S. Immigration and Customs Enforcement's Enforcement and Removal Operations, which did not elaborate. They arrived in Turkey on Thursday morning, said his former attorney, Jonathan Turley.

The long-planned deportation was finally made possible after federal prosecutors last June dropped a criminal contempt indictment against Al-Arian.

A U.S. Department of Justice spokesman declined to comment, but Al-Arian released a statement through Turley.

"After 40 years, my time in the U.S. has come to an end. Like many immigrants of my generation, I came to the U.S. in 1975 to seek a higher education and greater opportunities," Al-Arian said. "But I also wanted to live in a free society where freedom of speech, association and religion are not only tolerated but guaranteed and protected under the law."

The couple has three adult daughters — the youngest is a college student — who live in the United States and two sons who live overseas. They also have four grandchildren, the oldest of them 3 years old.

"We look forward to the journey ahead and take with us the countless happy memories we formed during our life in the United States," Al-Arian wrote.

USF spokeswoman Lara Wade declined to comment on the new developments.

It's unclear why Turkey was chosen or what the couple will be doing there, though friends say they expect Al-Arian will continue to write and look for university work.

The couple learned the government was moving ahead with deportation to Turkey only recently and had a couple of months to get their affairs in order, said Mel Underbakke, a Tampa-based director for the National Coalition to Protect Civil Freedoms

More than 80 Tampa area friends threw a going-away party on Jan. 17 at the First United Church of Tampa, she said. And last Saturday night, about 100 people gathered at a Virginia mosque for a dinner.

When Al-Arian spoke to attendees at the events, Underbaake said, he expressed a deep appreciation for the U.S. "One concept he repeated was how much he loves the values of this country," she said.

At the Virgina event, his friends expressed admiration for the Al-Arians and sadness about their departure, she said.

"Why would you want to deport a person like that?" she said.

Al-Arian, the son of Palestinian refugees, was born in Kuwait and came to the United States in 1975. In 1986, he and his family came from North Carolina so he could teach computer science at USF. He founded a Muslim school and co-founded the World and Islam Studies Enterprise, a think tank on Middle Eastern topics at USF.

He isn't the only member of his family to be accused of terrorist activities. His http://tbtim.es/dte"> brother-in-law, Mazen Al-Najjar, a former USF instructor, was jailed for almost five years on accusations he had links to Palestinian terrorists. Although never charged with a crime, he overstayed his student visa and was deported in August 2002.

In 2003, federal prosecutors in Tampa filed an indictment alleging Al-Arian was a leader of the Palestinian Islamic Jihad and complicit in the murder of civilians. Al-Arian ended up taking a plea deal on greatly reduced charges after a federal jury in Tampa did not convict him following a lengthy trial.

The deal included a recommendation for time served and immediate deportation — possibly to Egypt, where he lived before he came to the United States.

Specifically, he admitted to conspiring to aid the PIJ by helping a relative with links to the group get immigration benefits.

"Much of the evidence the government presented to the jury during the six-month trial were speeches I delivered, lectures I presented, articles I wrote, magazines I edited, books I owned, conferences I convened, rallies I attended, interviews I gave, news I heard, and websites I never even accessed," Al-Arian said in Thursday's statement. "But the most disturbing part of the trial was not that the government offered my speeches, opinions, books, writings, and dreams into evidence, but that an intimidated judicial system allowed them to be admitted into evidence. That's why we applauded the jury's verdict."

But instead of Al-Arian being expelled, the legal drama continued when prosecutors in Alexandria, Va., sought his testimony in a separate investigation there. He refused, saying he had carefully negotiated the Florida plea deal to exclude the usual requirement to cooperate with government investigations. But appellate courts ruled that prosecutors were within their rights to subpoena Al-Arian in the new case.

They sought his testimony in a long-running, terror-related grand jury investigation focusing on a Herndon, Va.,-based organization called the International Institute of Islamic Thought, which was raided by the FBI in 2002 and had provided funding to the think tank Al-Arian founded.

In 2008, prosecutors in Virginia filed criminal contempt charges against him for his refusal to testify about that despite a grant of immunity. The case languished, with the Al-Arians living under house arrest at their daughter's Virginia home, until a federal prosecutor agreed to dismiss the indictment last June.

"The Al-Arian case will remain a chilling chapter in our history," Turley, the former lawyer for Al-Arian, wrote on his blog. "The treatment of Dr. Al-Arian after his acquittal on most of the charges was widely viewed as a shocking abuse of the system and a flagrant violation of agreement reached with the Justice Department.''

Times Researcher John Martin contributed to this report. Contact Jodie Tillman at jtillman@tampabay.com or (813) 226-3374. Follow @jtillmantimes.