Inspector General Kristine Hamann yesterday told a state Senate Republican investigative panel that her office is capable of acting as a watchdog over the governor’s office and that she is opposed to proposed legislation that would force her to turn over executive chamber inquiries to the state attorney general.

“I would be stripped of my ability to be an inspector general in the most important cases,” she said. “Your proposal would deprive the governor of the ability to investigate his own staff.”

In testimony before the Senate committee, Ms. Hamann gave her most detailed defense of her office’s investigation into allegations that Governor Spitzer inappropriately used state police to collect damaging information about the Senate Republican leader, Joseph Bruno.

Senate Republicans have accused Ms. Hamann, who was appointed by Mr. Spitzer, of failing to exercise the subpoena powers of her office, which is supposed to review allegations of corruption, fraud, and abuse in the governor’s office and hundreds of other state agencies.

Ms. Hamann’s office never issued a report; instead, it concurred with a report by Attorney General Cuomo’s office, which conducted a parallel probe and faulted two Spitzer officials for conspiring against Mr. Bruno.

Lacking subpoena power, Mr. Cuomo’s office was denied the opportunity to interview two key aides to the governor, Mr. Spitzer’s director of communications, Darren Dopp, and the governor’s chief of staff, Richard Baum. He could have been given the power had Ms. Hamann’s office — which did not perform any interviews with top Spitzer officials, or subpoena e-mails and other documents — referred the case to him.

Republican criticism of the two probes has triggered inquiries by the state ethics commission and the Albany County district attorney’s office.

The legislation they proposed would effectively make Mr. Cuomo, a Democrat, the overseer of the Spitzer administration. It would require the inspector general to refer investigations to the state attorney general “in cases where an alleged incident of corruption, fraud, criminal activity, conflict of interest or abuse relates to an employee of the executive chamber involving his or her employment or business dealings.”

Ms. Hamann, a former prosecutor in the Manhattan district attorney’s office, provided several reasons for why she cut short her inquiry into the governor’s office and didn’t refer her case to Mr. Cuomo.

She said she terminated the investigation after it determined there was a conflict of interest connected to Richard Baum, the governor’s chief of staff, whose involvement in the scheme is now under scrutiny by ethics and Albany County investigators. By statute, Ms. Hamann reports directly to Mr. Baum.

She also said she was hampered by a “political firestorm” surrounding the case that made it impossible for the office to preserve an appearance of objectivity. Although her office never interviewed any senior administration official, it concluded that continuing with the probe wouldn’t have added anything to the report issued by the attorney general. Speaking to reporters afterward, Ms. Hamann said she “did not know” that her office had not interviewed Messrs. Dopp and Baum, according to the Daily News’s political blog.

Republican committee members said they were dissatisfied by her responses.

“I have a tremendous amount of questions and so do the people of the state of New York about how people could conclude investigations without talking to anybody, without having subpoenaed anybody, and without putting anybody under oath, and come to a decision that no criminal activity has taken place. It’s beyond me,” a Republican senator of Brooklyn, Martin Golden, told Ms. Hamann.

“She did stupid things,” Mr. Golden said in an interview afterward. “How did you close an investigation when you don’t know what transpired? At the end of the day, heads have to roll here.”