The Democratic Westchester County executive, Andrew Spano, in the fall of 2001 explicitly warned a former top deputy to him to cut off his support for a Democratic candidate running against the Republican district attorney, Jeanine Pirro, or pay a stiff price, the aide is claiming.

The aide, Jay Hashmall, said the warning came after Mrs. Pirro telephoned Mr. Spano to deliver a threat. “Andy Spano came into my office and told me that he just got off the phone with Jeanine Pirro who was extremely angry and wants me silenced or there would be serious consequences,” Mr. Hashmall told The New York Sun in a telephone interview yesterday.

His story, a tale of alleged political collusion and prosecutorial abuse, had faded in Westchester political lore until it was discovered that it figured prominently in a 15-page complaint against Mrs. Pirro that a former Republican mayor of Yonkers, John Spencer, delivered to Attorney General Eliot Spitzer in June 2003. Mrs. Pirro’s opponent in the state attorney general’s race, Andrew Cuomo, has seized on the letter to bolster his campaign attacks against her.

Mr. Hashmall said Mrs. Pirro’s anger was initially sparked by his involvement in a candidates’ forum in mid-2001 at which he had praised Mrs. Pirro’s challenger, Anthony Castro, and criticized Mrs. Pirro for signing the fraudulent tax returns for which her husband, Albert Pirro, was convicted in 2000.

Mr. Castro, a former Bronx assistant district attorney, was an underdog candidate who had emerged as a competitive threat in the aftermath of the tax fraud conviction and imprisonment of Pirro.

Mr. Hashmall didn’t heed the warning. Instead, he attended a fund-raiser for Mr. Castro in September 2001 that took place at the home of an assistant to the county executive, Robin Schlaff, a longtime Democratic activist.

Shortly after, Mr. Hashmall said, Mrs. Pirro made good on her threat by announcing an investigation into no-bid contracts totaling $2.4 million that he approved more than a year and a half earlier for one of his former law clients, Ralph Arred, a former Democratic Party leader in Yonkers who ran construction contracting companies.

Mr. Hashmall was accused of using his position as acting chairman of the county contracts board to steer four no-bid contracts to Mr. Arred’s County Site Development Corp, which was hired to repair parks and reconstruct a dam in northern Westchester months after Hurricane Floyd. Mr. Hashmall said he notified the board of his connection to Mr. Arred before approving the contracts, which came at the recommendation of the public works commission.

Mrs. Pirro then served grand jury subpoenas to Mr. Hashmall and three other assistants who attended the fund-raiser for Mr. Castro.

No charges were ever brought against Mr. Hashmall or any of the other assistants, but news of the investigation and the grand jury proceedings splashed on the front page of the Journal News — timed right before the November election — quickly led to his downfall.

On November 30, Mr. Spano fired him from his job, according to Mr. Hashmall.”I never would have thought that Andy Spano would fire me,” he said. “I couldn’t believe he could stoop that low. He capitulated to her to wishes,” referring to Mrs. Pirro.

Ms. Schlaff was also forced to resign. One of two other county executive employees who were issued subpoenas, David Meyers, left his job and committed suicide a year later, jumping out of his mother’s building. Meyers’s brother “mentioned at the funeral that he was distraught about what happened to me,”Mr. Hashmall, who said he attended the service, said.

“It’s a story of Westchester County being Tammany Hall,” Mrs. Schlaff, now a general practice lawyer, told The New York Sun.”The party was at my house … I had nothing to do with the contracts.”

Mr. Spencer, who is the Republican Party’s choice to unseat Senator Clinton, said in his letter to Mr. Spitzer that Mr. Hashmall was the victim of a secret nonaggression pact agreed to by Mrs.Pirro, Mr. Spano, and the county clerk, Leonard Spano.

He wrote that the “three incumbents agreed to secretly support and help each other. Each agreed that they would steer their political party to put up weak candidates, they would not share any significant amounts of their substantial campaign funds with these weak candidates and they would run all together as a team on several minor party ballots.”

A spokesman for the Pirro campaign, John Gallagher, said the investigation wasn’t a case of retribution but “uncovered evidence that led to the prosecution and conviction of Ralph Arred on charges of federal tax evasion.”

Mr. Arred in April reportedly pleaded guilty to failing to file personal incomes taxes between 2001 and 2004 and for failing to pay the government taxes that he deducted from employees at his firm, Arred Electrical Contracting Corp.

The Journal News reported that the case was referred to federal prosecutors and that none of the charges were related to the contract awards. A spokeswoman for Mr. Spano, the county executive, refused to comment on Mr. Hashmall’s accusations.