In a surprise development in the state police scandal, Governor Spitzer yesterday submitted to questioning by Albany County investigators, who are trying to determine if his administration committed a crime in connection with its scheme to discredit the state Senate Republican leader, Joseph Bruno, a source close to the district attorney’s office said. It was the first time investigators have formally questioned the governor, who has insisted repeatedly that he was unaware that his aides had done anything improper. Sources say Mr. Spitzer was not interviewed under oath.

The interview of the governor comes at what is believed to be the tail end of District Attorney David Soares’s seven-week criminal inquiry.

Mr. Soares’s public integrity unit has interviewed several other high-level aides to the governor and was expected to make public its conclusions by the end of the week.

The district attorney’s final report is sure to face intense scrutiny from Senate Republicans, who have questioned Mr. Soares’s decision not to put key witnesses under oath.

Mr. Bruno has demanded that the governor submit to a sworn interview, and he has questioned why Mr. Soares had not yet talked to the governor directly.

Yesterday, Senate Republicans announced that they had hired a former U.S. attorney, Joseph diGenova, to serve as a special counsel for their own probe of the matter.

Republicans have accused the administration of not cooperating with investigators.

Even if Mr. Soares does not find that a crime took place, he could determine whether Mr. Spitzer or his aides provided conflicting answers about their knowledge of the controversy.

In July, Attorney General Cuomo’s office released a report alleging that Mr. Spitzer’s communications director, Darren Dopp, and his police liaison, William Howard, directed the state police to gather information about Mr. Bruno’s use of security escorts and planted the records in the press in the hopes of generating negative coverage on the senator. The governor endorsed Mr. Cuomo’s report and apologized for his administration’s actions.

The state ethics commission is looking into whether the governor’s office violated state ethics laws, combing through thousands of e-mails turned over by the Spitzer administration, and subpoenaing Mr. Dopp.

Mr. Soares and the ethics commission launched their own probes after it was disclosed that Mr. Cuomo was unable to interview aides to the governor because he lacked subpoena power. A spokeswoman for Mr. Soares’s office declined to comment on the investigation because it is not completed.