Al Qaeda's reported nuclear whiz kid — a "tantalizing terror figure" with a $5 million bounty on his head — was the figure investigators had hoped to snag in their 18-month probe of a plot to blow up a New York airport, the New York Post reported Monday.

The name of Adnan Gulshair el-Shukrijumah, reportedly the man Usama bin Laden tapped to lead a previous plot to detonate nuclear bombs simultaneously in several U.S. cities, came up at several points in taped conversations during the probe, law-enforcement sources familiar with the investigation told the paper.

Three Muslim men were nabbed Friday in the alleged plan to attack John F. Kennedy International Airport, which involved exploding a jet-fuel pipeline that snakes from New York to New Jersey. A fourth suspect is at large.

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Given Shukrijumah's notoriety in the terror world and the fact that he grew up in Guyana, as did three of the suspects, investigators immediately homed in on him, the Post reported.

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"We thought he could be the invisible hand. He's always in the shadows, particularly in [the Caribbean]. He's passed through it, he's known, his name came up in the conversations," one law-enforcement official told the Post. "He would have been the prize."

Meanwhile, federal authorities said the informant who helped break up an alleged plot to bomb a fuel pipeline feeding the city's busiest airport was so convincing to the suspects that they actually thanked God he was with them.

The suspects, accused mastermind Russell Defreitas, 63, is in custody in New York, where he will have a bail hearing on Wednesday.

But two other suspects, Kareem Ibrahim and Abdul Kadir, a former member of Guyana's Parliament, were in Trinidad and will fight extradition to the United States, their lawyer, Rajid Persad, told a Trinidadian court on Monday.

The two made their initial court appearance there on one count each of conspiracy to commit a terrorist act against the government of the United States. The judge set a bail hearing for June 11 and an extradition hearing on Aug. 2.

The informant made several overseas trips to discuss the plot against the airport, even visiting a radical Muslim group's compound in Trinidad, officials said. He also joined the plotters on airport surveillance trips — where authorities were waiting, they said.

The suspects were convinced the informant was guided by a higher purpose: The ringleader believed the informant "had been sent by Allah to be the one" to pull off the bombing, according to a federal complaint.

The four-person plot, revealed Saturday, demonstrated the growing importance of informants in the government's efforts to combat terrorism, particularly as smaller radical groups become more aggressive.

Tom Corrigan, a former member of the FBI-New York Police Department Joint Terrorism Task Force, said the Kennedy airport case and the recent plot to attack Fort Dix illustrated the need for inside information. Six men were arrested in a plot to attack soldiers at the New Jersey military base after an FBI informant infiltrated that group.

"These have been two significant cases back-to-back where informants were used," Corrigan said. "These terrorists are in our own backyard. They may have to reach out to people they don't necessarily trust, but they need — for guns, explosives, whatever."

Without informants, Corrigan said, investigators are often left with little more than educated guesswork. "In most cases, you can't get from A to B without an informant," said the ex-NYPD detective.

In the Kennedy airport case, the informant was a twice-convicted drug dealer who found himself in the midst of a terrorist plot conceived as more devastating than the Sept. 11, 2001, attacks.

"Would you like to die as a martyr?" the informant was asked, according to the indictment.

He unhesitatingly replied yes and soon was making surveillance trips around the airport — the "chicken farm," as the planners dubbed their target.

Authorities said the JFK scheme was an example of homegrown terrorism. The man accused of being the mastermind, Defreitas, 63, immigrated to the U.S. more than 30 years ago, but he told the federal informant that his feelings of disgust toward his adopted homeland had lingered for years.

"Before terrorism started in this country," he said in one secretly recorded conversation.

Defreitas, in custody Sunday pending a bail hearing, was arrested Friday night outside Brooklyn's Lindenwood Diner — a spot once bugged by federal officials tracking former Gambino family boss John A. "Junior" Gotti.

The four Muslim men accused in the JFK plot didn't turn to Pakistan, Iran or Afghanistan for support after targeting the airport, home to an average of 1,000 daily flights and 45 million passengers annually.

Instead, according to a federal complaint, the informant and defendants Kareem Ibrahim and Defreitas visited a compound belonging to Jamaat al Muslimeen, a radical Islamic group known for launching a bloody 1990 coup attempt in Trinidad that involved taking the prime minister and his Cabinet hostage. It left 24 people dead.

Though Jamaat al Muslimeen did have contact with the men accused in the Kennedy airport plot, it is not accused of offering them any support. The group, whose followers are largely black converts to Sunni Islam, has faded as a political force in Trinidad as its leader, Yasin Abu Bakr, fends off criminal charges of inciting violence.

The rebels in the 1990 raid on Parliament surrendered and were pardoned.

When Defreitas discussed his radical "brothers" with the informant, he made it clear they were not Arabs, but from Trinidad and Guyana.

The complaint made clear the informant had deeply infiltrated the group. Defreitas, a retired JFK airport cargo worker, made four reconnaissance missions to the airport, authorities said. They captured each one on audio and video equipment.

Ibrahim and another suspect, Abdul Kadir, were in custody in Trinidad awaiting extradition hearings. Officials identified Kadir as a former mayor of a Guyanese town and a member of the country's Parliament.

Authorities in Trinidad were still seeking a fourth suspect, Abdel Nur.

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The Associated Press contributed to this report.