COHOES — An FBI investigation into the business dealings of Cohoes Mayor Shawn M. Morse was revealed this week when federal agents interviewed the mayor at his residence early Monday morning.

The FBI's unannounced visit took place about 6 a.m. About an hour later, the federal agents visited the Kosciusko Avenue residence of the city's director of operations, Ralph V. Signoracci, who was served with a federal grand jury subpoena, according to a person familiar with the investigative activities.

Signoracci is a county legislator and has served for years as treasurer of Morse's various political campaign accounts, which are one focus of the investigation, the source said. His residence is listed as the headquarters of Morse's campaign accounts.

Signoracci, 44, and Morse, 51, did not respond to written requests for comment. Signoracci's attorney, James E. Long, declined to comment. Joseph Ahearn, an attorney for Morse, was in court for an unrelated case Wednesday and could not be reached for comment.

Cohoes Common Council President Chris Briggs on Wednesday said he had heard "rumors" about the FBI probe this week, but had not discussed the matter with Morse.

"I didn't go out and try to verify anything," Briggs said. "I would have assumed I would have heard from the mayor, but I did not. ... All I heard was the FBI was involved, collecting files. I'm not sure what that meant."

FBI agents have also interviewed at least one other city official as part of their ongoing probe, according to the source familiar with the investigation.

The investigation includes an examination of Morse's government activities; agents are also probing vacations that Morse has taken, including trips with city police Capt. Todd Pucci, who is the mayor's close friend. Last November, Pucci, who is a part-time public safety commissioner in the village of Altamont, was among the officers who responded to Morse's residence when the mayor's wife, Brenda, called 911 and told a dispatcher her husband had grabbed her by the neck and thrown her to the ground.

Morse, who has denied he choked his wife, has not been charged for that alleged incident, which remains under investigation by multiple law enforcement agencies. The State Police are also probing allegations made by Morse's 16-year-old daughter that he physically abused her last year, including choking her and punching her in the head.

In May, two FBI agents went to the Cohoes' residence of Jeff Bagley, 52, to interview him about his arrest in January by Cohoes police on the basis of a criminal complaint that had been filed by Morse's cousin Barbara J. Borden, who alleged Bagley harassed and threatened her in Facebook posts.

The allegations, which led city police to obtain a warrant and arrest Bagley, were later disproven. Bagley, 52, has filed a claim against the city alleging his arrest was retribution for speaking out about prior domestic abuse allegations leveled against Morse.

The unrelated FBI probe of Morse's business dealings includes an examination of the mayor's various sources of outside income, according to people briefed on the investigation.

Morse appointed himself as chief executive officer of the city's Industrial Development Agency after he was sworn in for his first term as mayor in 2016. IDA funds are used to pay Morse $15,000 a year for that role, under a line in the budget listed as "professional services contracts."

Last year, in the wake of Brenda Morse's 911 call, the mayor was placed on leave from his job as a labor relations representative for United Public Services Employees Union. Kevin Boyle, president of UPSEU, on Wednesday said that Morse's employment with their union ended last year.

About a year ago, the Justice Department subpoenaed banking records as part of the examination of the mayor's activities, according to a law enforcement official briefed on that aspect of the investigation.

A spokesman for the U.S. attorney's office in Albany said their general policy is to not comment on — or even confirm the existence of — ongoing investigations.

Before being elected mayor of Cohoes in 2015, Morse was chairman of the Albany County Legislature and had been a Cohoes firefighter from 1989 to 2015.