Defense attorneys have accused federal agents of trying to intimidate witnesses in the case of a Woodbridge man alleged to have terrorist ties, prompting an immigration judge to conduct an unusual hearing into the allegation.

Majed Hajbeh, 41, was recently found guilty of obtaining an immigrant visa in 1992 based on incorrect information. He has appealed to the judge to let him remain in the country, saying that he made mistakes in filling out the application and that he, his wife and seven children would face extreme hardship if forced to leave.

Immigration attorneys say the case shows how U.S. authorities are using immigration charges to deport Muslims suspected of terrorism links. Hajbeh was convicted in absentia in a series of bombings in 1998 in his native Jordan. He denies involvement in those attacks, which caused property damage but no casualties.

Immigration Judge Wayne Iskra held a special hearing Thursday after a witness, Priscilla Nabulsi, said she had been visited by an Immigration and Customs Enforcement agent after her testimony on behalf of Hajbeh in November.

"The real reason for the visit was to intimidate witnesses in this case," Hajbeh's attorney, Kimberly Kinser, said at the court hearing in Arlington. She produced two other witnesses for Hajbeh who said that they, too, had been contacted by federal agents after testifying.

Prosecutors for Immigrations and Customs Enforcement denied the accusation.

The agent, T. Anthony Langeland, testified that he had questioned Nabulsi because he was investigating another possible violation -- that Hajbeh might have lied on his application for citizenship a few years ago. He said Nabulsi was cooperative and friendly during his visit to her trailer home in Murfreesboro, Tenn.

But the judge indicated that he was concerned.

"Why did you find it necessary to go interview a witness while the trial was going on?" Iskra asked. Langeland said in his testimony that he was unaware that Nabulsi had just testified in the case.

Iskra said it was beyond the jurisdiction of the immigration court to rule on whether the agents had acted improperly. But, he said, their actions could reflect on the government's handling of the case. He is expected to issue a ruling on the appeal in a few weeks.

Nabulsi said she became nervous during the Dec. 1 visit when Langeland displayed an envelope with subpoenas and said she could have been summoned to appear before a grand jury if she had not answered his questions. Nabulsi testified that she decided to stop cooperating with Hajbeh's defense, but later changed her mind.

Two other witnesses, Fares Masri and Mohammad Azzawe, both friends of Hajbeh's from Northern Virginia, said they had received visits from the an FBI agent after testifying in his defense. Masri said the agent, Andrew Wade, had told him that he "wanted to know about other members of the community." Masri said he told the agent to contact his lawyer.

Azzawe also said he referred Wade to his attorney. Azzawe said the agent wanted "to pay me money to work with him." He said he declined and continued to appear in the Hajbeh case.

An affidavit by Wade was submitted in court but was under seal, according to a spokeswoman for the FBI's Washington field office, Debbie Weierman, who declined to comment further.

Thursday's hearing got off to a dramatic start when the judge told security guards to allow Hajbeh's supporters to enter the tiny courtroom. The guards refused, citing security reasons. They had allowed two journalists to enter, however.

"I'm the judge, and nobody has informed me for the reason for this security," Iskra said. "I'm the judge!"

He suspended the hearing, to confer with the attorneys and await a resolution of the matter by the Department of Homeland Security, which controls access to the building. About 45 minutes later, Iskra resumed the session, saying, "This courtroom is now open."

Ernestine Fobbs, a spokeswoman for Immigration and Customs Enforcement, which is part of Homeland Security, said security had been tightened because "it's a sensitive case, and we anticipated a large crowd of people."

She said the guards were apparently misinformed about letting people into the hearing.