By RALPH BLUMENTHAL

He is, by all accounts, the linchpin of the case against a ring accused of plotting to blow up New York City. He is a Government informer crucial enough to be shuttled between international hideouts, a witness so sensitive that the local F.B.I. director was suspended after making the merest reference to him on television.

So it should be of scant surprise that Emad Eldin Aly Abdou Salem remains a figure of intrigue six months after disclosure of his role in foiling what the authorities call a terrorist plot to assassinate political leaders and bomb the city's landmarks.

Elements of a Spy Epic

But as he awaits his courtroom debut, probably in the fall, in the Federal trial of Sheik Omar Abdel Rahman and more than a dozen co-defendants, Mr. Salem is shedding some of his mystery -- in part by his own compulsive unwillingness to remain in the shadows. Although in the witness protection program since June, he has been making regular calls to an ex-wife, associates and even some reporters.

In the process, contradictory tales of his exploits are emerging in a case in which his credibility and deeds are likely to become central issues.

In all, he comes across as an elusive figure whose personal and professional entanglements are part soap opera and part spy epic. He has had three wives, overlapping undercover incarnations and as many faces as his changing likeness in family photographs: fiercely bearish in a bristly black beard, rakish in a droopy mustache, jovially clean-shaven in a wedding tuxedo.

Mr. Salem, 43, a longtime Egyptian intelligence agent, has not responded to numerous messages from The New York Times, and Federal officials will not discuss him. But a two-month inquiry has turned up a wealth of new information about his resilient ties to Egyptian intelligence, his recruitment by the Federal Bureau of Investigation and the Immigration and Naturalization Service, and his complicated relationship with his F.B.I. case agents, whom he secretly tape-recorded.

Mr. Salem's American ex-wife, Barbara Louise Rogers, saying she remained deeply attached to him despite their divorce a year ago, backed up some of his claims but said he was prone to machinations and often left her in the dark. "Emad said he was like a spider," she said. "He had to spin a web to get out."

Speaking about Mr. Salem in a series of interviews documented by telephone bills, letters and family photographs, Ms. Rogers said he called her almost daily, sometimes from locations he portrayed as six or seven time zones distant.

Schemes Unfold on Tapes

According to charges in the indictment and to evidence cited in other court papers, Mr. Salem, posing as a co-conspirator, recorded conversations last year with Mr. Abdel Rahman and other defendants regarding the assassination of President Hosni Mubarak of Egypt, Senator Alfonse M. D'Amato and Assemblyman Dov Hikind, the bombing of the United Nations and Hudson River tunnels and a suicide attack on the Manhattan Federal office building that houses the F.B.I. On the bootleg tapes he also cites schemes to explode 12 bombs at targets including Grand Central Terminal, Times Square and the 47th Street diamond district.

For his undercover efforts, Mr. Salem was getting $500 a week, and the tapes reflect his haggling with the bureau over a payment as high as $1 million after his testimony.

If the conversations he taped with the defendants are as incriminating as the prosecution contends, it may not matter much what derogatory material the defense can marshal against Mr. Salem. But with his tangled history and bootleg recordings, he has clearly provided much potential ammunition to his detractors.

One defense lawyer, William M. Kunstler, has signaled an intention to use Mr. Salem's self-recorded words to argue that he and the F.B.I. fabricated a conspiracy to cover up a central role in the earlier World Trade Center bombing.

Mr. Salem himself complains repeatedly in the bootleg tapes that by insisting that he surface as a potential witness instead of staying under deep cover as an intelligence source, F.B.I. supervisors blew a chance to thwart the Feb. 26 bombing.

Justice Department officials, while privately deriding the claim, have refused to comment publicly, citing the sensitivity of the case. And when the head of the F.B.I.'s New York office, James Fox, answering a question on television last month, took three sentences to dismiss Mr. Salem's claim as baseless, the bureau's director, Louis J. Freeh, angrily suspended Mr. Fox three weeks before he retired from a 31-year career.

The Emigrant Leaving Luxury To Drive a Cab

According to immigration records, Mr. Salem arrived in New York City from Cairo on Sept. 25, 1987. Background information provided confidentially by the Government to the court and defense lawyers describes him as an army retiree who had agreed to report to Egyptian authorities on any contact with five members of the Egyptian armed forces who had failed to return home after American training.

It is unclear what impelled him to leave behind his two young children from a first marriage, trading a life of privilege with a military driver at his disposal for a life driving cabs and stalking shoplifters in New York City. Ms. Rogers dismisses the account of his retirement, saying he was specifically sent to hunt for the five Egyptian officers. "That was one of many things he was doing here," she said. "Nothing was casual with them. He came here with a specific agenda."

Mr. Salem himself stumbled over the episode when asked in an F.B.I. polygraph test whether he had come on a mission. "I said 'no,' and then 'no and yes' and 'yes and no,' " he recounted later to a sympathetic agent on the bootleg tapes.

In resumes, Mr. Salem (who in the United States pronounced his name eye-MAD SALE-em) said he had spent from 1970 to 1987 in the Egyptian army, receiving a degree from the military technical college in Cairo in 1974 and retiring with the rank of major. He listed "specialized training in plastic explosives" and anti-terrorism measures, photography and surveillance. Round-faced and well muscled at 5 feet 9 inches and 200-plus pounds, he also described himself as a national champion marksman and a judo and wrestling champion.

'Bodyguard to V.I.P.'

He also listed "bodyguard to V.I.P.," a reference to claims that he had been wounded in the 1981 assassination of President Anwar el-Sadat, claims that Ms. Rogers said she believed based on his body scars and his photos of the shooting site.

Egyptian security officials disclaim any knowledge of his role. Hamdi Fouad, Washington bureau chief of the Egyptian Government newspaper Al-Ahram, also cast doubt on Mr. Salem's claims. As someone who witnessed the killing, Mr. Fouad said he did not believe Mr. Salem was ever part of the Sadat security detail.

But he said he had a cordial relationship with Mr. Salem and had received several recent calls from him eager to explain his informer's role. "He said he was doing this to defend Egypt" and "he didn't care for the money," Mr. Fouad said.

A neighbor who later befriended Mr. Salem in New York, Ron Wollman, said Mr. Salem told him he had run an Egyptian military prison and had sought to quit the army in disgust after seeing a dog used to sodomize an anti-Government professor. He said Mr. Salem told of being held in the same prison after an arrest for political opposition on a trip back to Egypt in 1989, fighting off snakes dropped into his cell and escaping by learning the code numbers of his cell's combination lock and fleeing naked into the desert.

Ms. Rogers said that Mr. Salem had indeed been jailed in 1989, but not for opposition to the Government. "He was the Government," she said. Instead, she said, the punishment was meted out because "they were horrified that someone at that intelligence level married an American citizen."

Settling Down A U.S. Marriage And Security Jobs

Ms. Rogers, then a marketing employee for Avon Products, said she met Mr. Salem through mutual friends two days after his arrival in New York at a tae kwon do studio on East 86th Street where they worked out. Two weeks shy of 34, she had grown up on an upstate farm and studied chemistry in college.

They wed six weeks later, on Nov. 8, 1987, in an Islamic ceremony. Ms. Rogers said their emotional attachment was such that she does not believe Mr. Salem married her for a green card or to obtain American citizenship. Six months later, they repeated their vows in a Christian ceremony at Marble Collegiate Church.

She said he then took a succession of jobs as a security guard, working at Henri Bendel and Bergdorf Goodman, among other stores, and at Graham Knowles Security Consultants, where he listed his responsibilities in part as "anti-industrial espionage responsibilities for major corporations in New York City." He also worked as a supervisor and investigator for Walla Security and Investigations Incorporated, which provided hotel guards.

Around the same time, he got a taxi license and spent hours with Ms. Rogers driving around the city to learn the streets. But he gave up hacking, she said, after an angry fare threw a two-cent tip in his face. "You have to understand," Ms. Rogers said, "this man had his own driver in Egypt."

Return Trips to Egypt

Meanwhile, she said, he made frequent trips alone back to Egypt, traveling there three times in 1988 and twice in 1989. It was on a trip in September 1989 that he was jailed for several days, she said.

Despite the jailing, Ms. Rogers said, he returned again to Egypt in March 1990 and took her along. She said they were "treated like royalty," met by security officials at the Cairo airport and housed in highly secure navy and army quarters. She said she could not account for the abrupt turnabout and reconciliation with the Government.

Mr. Salem later made at least three more trips alone to Egypt, she said, and their telephone bills show hundreds of dollars in calls to Egypt -- as well as at least two unexplained calls in 1990 and 1992 to the switchboard of the Central Intelligence Agency in McLean, Va.

In September 1989, Mr. Salem was hired as an engineer at a hotel the Walla agency had served, the Woodward on Broadway at 55th Street, and later given a free apartment in a building next door.

The F.B.I. Recruit A New Citizen Goes Undercover

According to Ms. Rogers, Mr. Salem's ties to the F.B.I. began against a backdrop of growing tensions over the Iraqi invasion of Kuwait, as an agent visited the hotel in 1990 to check on Mr. Salem as a well-connected Egyptian who had made repeated trips abroad. Mr. Salem took the opportunity to offer his services, Ms. Rogers said.

The F.B.I. soon gave him a chance to test his skills, she said, as the agent returned to the Woodward in early 1991 to check on some Russians suspected of smuggling guns and drew on Mr. Salem's knowledge of the hotel.

Meanwhile his trips to Egypt continued. Ms. Rogers said that he returned there in the summer of 1991 -- when he became an American citizen -- in October 1992 and in January 1993.

In November 1991, when an Egyptian contractor, El Sayyid A. Nosair, went on trial in the killing of the Jewish extremist leader Rabbi Meir Kahane in a Manhattan hotel a year before, the F.B.I. asked Mr. Salem for help in penetrating Mr. Nosair's circle of supporters, the Government material says.

About the same time, it says, Mr. Salem was "solicited" by Sheik Omar Abdel Rahman, a blind Egyptian cleric, "to murder the President of Egypt." Fearing an attempt on the life of President Mubarak, it says, the F.B.I. agreed that Mr. Salem could pass the information on to Egyptian intelligence authorities as long as he did not reveal he was working with the F.B.I.

Whether Mr. Salem complied and deluded the Egyptians about his relations with the F.B.I., or whether he had already informed the Egyptians and thus deluded the F.B.I. -- or whether he misled both -- is not clear. But clearly, he could scarcely have been straightforward with both.

Trouble at Work A Bad Fall And New Behavior

Mr. Salem's last months at the Woodward were marked by conflict. In November 1991, as he was infiltrating the Nosair circle for the F.B.I., he took what he described as a flying fall off a ladder in the boiler room and landed on his head. The hotel manager, Kanwar Singh, said the episode ushered in a marked behavior change in Mr. Salem, who he said began shirking work.

Mr. Singh said hotel employees complained that Mr. Salem, who had become romantically involved with a jewelry designer, was pressuring them to buy jewelry and had threatened them with a gun. He also said that he had received a court order to garnishee a security guard's salary after Mr. Salem, without the guard's knowledge, obtained a Mastercard in his name and ran up unpaid charges. The guard, Mohammed Abulbaqi, declined to be interviewed but Ms. Rogers and hotel employees corroborated the account.

In the spring of 1992, Mr. Salem was fired from the Woodward. Four months later, on July 28, 1992, Mr. Singh said, dozens of immigration agents accompanied by Mr. Salem raided the hotel, arresting workers without proper papers. Mr. Singh said he told the supervisory agent, Perry Kao, that Mr. Salem was barred from the premises and Mr. Salem was forced to wait outside. Mr. Kao and an immigration spokesman declined to comment, but the Government's background letter on Mr. Salem confirms his cooperation with immigration.

Around that time, the bootleg tapes show, he and the F.B.I. broke angrily. But after the trade center bombing, Ms. Rogers said, he went back to work for the bureau, using a camera concealed in a belt buckle and a body recorder hooked up through the zipper of his pants.

Trouble at Home After a Divorce, Keeping in Touch

In the meantime, his marriage with Ms. Rogers fell apart. In 1990, they separated and he later moved into the apartment of the jewelry designer, Karen Ohltersdorf, on the Upper West Side, sending for his son and daughter from Egypt to live with them. An employee at the Woodward said that in late 1991, he and a co-worker bore witness to the Muslim marriage of Mr. Salem and Ms. Ohltersdorf, although he and Ms. Rogers were still married.

In January 1992, with Mr. Salem seeking a divorce, Ms. Rogers went to Family Court to complain that he was stalking her and "using obscene and abusive language," according to her petition. It also said he threatened her with "an extremely graphically violent flier" -- a copy of an Arabic language newspaper, faxed from Ms. Ohltersdorf's apartment, bearing a photograph of a naked man being tortured on a pole.

But Ms. Rogers said she and Mr. Salem became cordial again despite his marriage to Ms. Ohltersdorf, who later went into the witness protection program with him.

Ms. Rogers said she saw him last in the emergency room of Mount Sinai Hospital on June 24, hours after the F.B.I. raid on a Queens bomb factory that prosecutors said smashed the plot to blow up New York. He had suffered an asthma attack brought on by the stress of springing the trap, Ms. Rogers said.

She had trouble finding him at first, she said. He was there under an alias.

Copyright 1994 The New York Times Company