Attorney Donnie Murrell was driving to the federal courthouse in Fort Pierce in June when his cell phone rang and he was asked to head back to West Palm Beach to represent a Palm Beach County man charged with wire fraud.

He had no idea what he was about to get into.

This week, four months after he agreed to represent career con artist Mohammed Agbareia on what appeared to be routine charges in an alleged stranded travelers scam, the West Palm Beach lawyer will learn if he will have to get top security clearance from the U.S. government to stay on the case.

While neither Murrell nor federal prosecutors can reveal it, Agbareia worked as an FBI informant and helped agents build a case against three Palm Beach County men who in June 2016 were charged with providing material support to a foreign terrorist organization, according to sources with knowledge of both cases.

Saying they fear Abgareia, 51, will reveal classified information, federal prosecutors have persuaded judges to close hearings in his fraud case and have filed documents under seal. In an order this month, U.S. District Judge Kenneth Marra said he received a declaration from "an official from an Executive Department of the United States government" that convinced him special precautions have to be taken to assure classified information is protected.

Those precautions, outlined in the Classified Information Procedures Act, will be hashed out during a hearing on Thursday.

No one familiar with how federal law enforcement officials flush out alleged terrorist plots is surprised that a confidential informant was involved in last year’s arrest of the three men — Gregory Hubbard, Dayne Christian and Darren Arness Jackson — who are accused of supporting the Islamic State.

But that the informant was indicted?

"That’s a little unusual to say the least," said Miami defense attorney Albert Levin, who represented one of the so-called Liberty Seven in a controversial 2006 terrorism case where prosecutors relied almost exclusively on FBI informants who posed as Al-Qaida agents.

That the government is invoking the classified procedures act is also unusual, Levin said. He said he suspects Abgareia, who has been convicted of charges in the United States and Canada for defrauding dozens of Muslim groups, worked for the FBI for years and the agency is worried about the impact his arrest could have on other cases.

While federal prosecutors have remained tight-lipped, Assistant U.S. Attorney Jared Strauss said at a recent hearing that he was worried about "graymail," which is when a defendant threatens to divulge classified information to force prosecutors to drop a case.

Exactly how long Agbareia, an Israeli national, has been working as an informant is unclear, but an Alabama newspaper reported he was working with the government 11 years ago.

In 2006, after being extradited from Canada, where he lived despite having been deported, Agbareia pleaded guilty in federal court in Alabama to a charge of conspiracy to commit wire fraud. Agbareia admitted he bilked $90,000 from mosques and Muslim groups throughout the country by posing as a representative of the Saudi-based Islamic Development Bank and offering financial aid, court records show.

Promising to travel to meet with them, he would call back, saying he was stranded at an airport. After convincing groups to wire him about $2,000 for airfare, he never showed up or repaid the money, prosecutors said.

In July 2006, he was sentenced to two years in prison. However, four months later, a judge reduced the sentence to time-served, citing a sealed motion from the U.S. Attorney’s office. Agbareia’s attorney told the Press-Register newspaper in Mobile that Agbareia was cooperating with the government. A year later, according to court records, he moved to West Palm Beach.

He continued to run similar schemes after he moved, said federal prosecutors in West Palm Beach who are pursuing Agbareia on fraud charges.

"Based on what Mr. Agbareia has already admitted to the FBI (after being convicted in Alabama) he re-started that scheme again in 2007 and seems to have been conducting it fairly continuously since then, really up until yesterday," Strauss told U.S. Magistrate James Hopkins on June 21 during Agbareia’s first-appearance hearing on the fraud charges.

That timetable, described in his indictment on six counts of wire fraud, overlaps with the work of the FBI informant who gathered evidence against Hubbard, Christian and Jackson in the terrorism case.

In court papers, FBI agents said that to befriend the three men, beginning in July 2015, their informant "posed as a follower of ISIL who wanted to travel to Syria to engage in violent jihad."

Prosecutors say that after the informant recorded hundreds of conversations with the three men about their desire to join the terrorist group and joined them at remote locations for target practice, the three were arrested in July 2016 when Hubbard tried to board a flight to Berlin at Miami International Airport. Hubbard, agents said, planned to travel from Berlin to Syria.

Agbarei’s arrest appears to be causing headaches for federal prosecutors in the terrorism case.

In April, Christian, 32, of Lake Park, and Jackson, 52, of Royal Palm Beach, both pleaded guilty to a charge of conspiring to provide material support to a foreign terrorist organization. Christian also pleaded guilty to being a felon in possession of a handgun. As part of their plea deals, they agreed to testify against Hubbard. Neither has been sentenced.

Hubbard, a 53-year-old Marine veteran who worked as an artist before becoming homeless, insists he did nothing wrong and is taking the case to trial.

But Hubbard’s trial, originally scheduled for this month, recently was moved to March 23 at the request of federal prosecutors.

Without mentioning Agbareia by name, Assistant U.S. Attorney Karen Gilbert said during a court hearing this month that "the informant’s indictment" forced prosecutors to rework its case. Instead of trying to get a jury to believe an informant who has been indicted, the man’s name has been removed from the government’s witness list, she told U.S. District Judge Robin Rosenberg.

Since the case turns on hundreds of hours of taped conversations the informant had with Hubbard and his co-defendants, an expert will be called to testify the recordings are authentic, Gilbert said.

Hubbard’s attorneys, assistant U.S. public defenders Anthony Natale and Vanessa Chen, have filed several motions accusing the government of targeting Hubbard because he is black and a Muslim. The motions also accuse the government of engaging in "outrageous conduct" by planting the idea for the so-called terrorist plot.

The parts of the motions referring to the background of the informant have been redacted. The motions have been put on hold while the public defenders review recent information they received from prosecutors.

Natale declined comment about the identity of the informant. Attorney Michael Salnick, who represents Christian, also declined comment. Attorney Julie Vianale, who represents Jackson, didn’t return a phone call.

Agbareia’s attorney also is accusing prosecutors of misconduct in his fraud case. Murrell claims Agbareia revealed his misdeeds to an FBI agent and a federal prosecutor in September 2016, three months after the men were arrested in the terrorism case. Yet, Murrell said in a court document, Agbareia wasn’t indicted until May 2017 and wasn’t arrested until June.

Murrell wrote that the government is hiding behind the classified procedures act to unfairly keep Agbareia locked in solitary confinement at the Palm Beach County Jail, where he is kept in a cell for 23 hours a day. He was placed in solitary confinement after the Sun Sentinel reported in June that he was the informant in the terrorism case.

"Since September 2016, the Government has known that any investigation or indictment of Mr. Agbareia would raise issues of national security," Murrell wrote in a motion to dismiss the fraud charges.

Officials at the Council on American-Islamic Relations said posing as a jihadist would have been easy for Agbareia. Using various guises, accents and ruses, he impersonated well-known Islamic leaders and activists when he called Muslims, saying he was stranded and asked them to send him money, said Ibrahim Hoooper, communications director for the Washington-based Muslim civil rights and advocacy organization.

"We’ve been dealing with this guy for decades," he said, noting that CAIR has put out alerts warning members not to fall for Agbareia’s pleas for money since at least 2000. "This guy’s good, you’ve got to give it to him," Hooper said. "He could get blood out of a turnip."

Sadly, he said, he’s not surprised government officials would use him to spy on Muslims. "We’re so used to dealing with warrantless surveillance of the Muslim community," he said. Still, he said, ultimately the government’s decision to use him as an informant may backfire.

"I wouldn’t trust him to tell me what time the sun comes up," Hooper said.