or the last year, New York's powerful real estate industry has been crackling with tension as federal investigators have pressed for the names of any property owners who may have knowingly benefited from a long-running bribery scandal.

That possibility all but evaporated late Monday afternoon. Albert Schussler, 85, the man indicted last February as the ringleader of the bribery scheme ? and the one person who investigators thought could tell exactly how the scheme worked and who benefited ? died after a severe stroke.

In the scandal, city assessors lowered the tax bills for many of Mr. Schussler's clients, the owners of some of New York's most valuable skyscrapers, hotels and apartment houses. So far, 15 assessors have pleaded guilty to bribery charges related to the allegations against Mr. Schussler.

A person close to him said that Mr. Schussler had decided to make a decision on Monday, the day he died, on whether to forge a defense for his trial, which was to begin Jan. 27, or plead guilty and tell all he knew about what Mayor Michael R. Bloomberg has called "the largest and most financially damaging corruption scheme ever conducted within city government."

But Mr. Schussler never got the chance to make the choice. He had a stroke at his East Side home on Sunday evening and never awoke from a coma. He died on Monday at New York Presbyterian Hospital.

"I would suspect that everybody who ever hired him, whether or not for illegal activity, is breathing a sigh of relief," said William K. Block, a tax lawyer and a former deputy commissioner at the Finance Department. "He couldn't do any good for anybody."

For investigators at the United States attorney's office and the city's Department of Investigation, who have tried to break a case against corruption in the city's Finance Department for at least 14 years, Mr. Schussler's death was frustrating. While the investigation is continuing, one law enforcement official said that investigators had been hoping that Mr. Schussler might provide information about developers who may have been involved in the scheme, and that his death had ended that hope.

There were those who mourned the man, who was by all accounts a philanthropist and a former city tax assessor who came to own such well-known New York landmarks as the Ansonia apartment hotel.

"Albert Schussler was a good and gentle person," said his lawyer, Stephen E. Kaufman. "The only plea he ever entered was `Not guilty.' He is therefore presumed innocent."

But after months of speculation and worrying about what might come out at the trial, the reactions from prosecutors and real estate executives were far different. His death was the first topic of conversation yesterday at the Real Estate Board of New York and at the luncheon meeting of the City Tax Review Bar Association.

Defense lawyers said that prosecutors had been pushing hard for the names of property owners who were aware of the bribery scheme and had hoped that Mr. Schussler would talk. "He had a lot of nervous owners and lawyers out there," one defense lawyer said of Mr. Schussler.

But the owners of the 562 properties that prosecutors claim benefited from the illegal scheme say they were unaware of any wrongdoing.

"There was never any insinuation of anything underhanded when I talked to him," Dr. Axel Stawski, a developer, said in an interview last year. "I was shocked."

Prosecutors vowed yesterday to press forward with the case. Two assessors, Joseph Iovino and Fady Sidaross, are to go on trial Jan. 27. A former investigator for the city's Department of Investigation has pleaded guilty to related charges, and another assessor, Joseph Marino, pleaded guilty in 2000 to taking over $4 million in bribes from Mr. Schussler in exchange for lowering the tax bills on some properties.

"The death of Albert Schussler is certainly a stunning event in this case," Rose Gill Hearn, commissioner of the investigative department, said in a statement released yesterday. "The impact of the tax assessors' corruption scheme with which he was charged cost the city an enormous revenue loss and will hurt the city for years to come. We will continue to pursue all remedies available for civil recovery of the money that should have gone into the city's coffers. The investigation will continue unabated."