BRIDGEPORT — Bridgeport businessman and FBI informant Michael DiFoggio, a key figure in the prosecution of several former politicians, was found dead of a suicide inside his plumbing and sewer business Tuesday night, authorities said.

DiFoggio, 58, was found shot inside M. DiFoggio Plumbing & Sewer Contractors Inc. in the 3200 block of South Shields Avenue at 10 p.m. Tuesday, according to the Cook County Medical Examiner's Office.

He suffered a gunshot wound to the head and his death was ruled a suicide by the Cook County Medical Examiner's Office Wednesday.

Working as a mole for the feds, DiFoggio secretly recorded conversations with former Cook County Commissioner Joseph Mario Moreno, among others, in a deal DiFoggio made in 2010 because of his "legal problems," the Sun-Times reported in July 2012.

Moreno had been appointed to a position with the Town of Cicero, and he believed DiFoggio wanted to use his Cicero connections to get approval for a waste transfer station development, according to FBI statements and the Sun-Times. Moreno said he wanted "a little piece" of the profits, according to the FBI.

In the most infamous quote DiFoggio got out of the former commissioner, Moreno said, "I don’t want to be a hog, I just want to be a pig. Hogs get slaughtered, pigs get fat.”

In fall 2012, DiFoggio pleaded guilty to tax evasion in federal court. He was facing as many as 2½ years in federal prison, but prosecutors said they likely wouldn't seek a sentence that long because of DiFoggio's cooperation in the investigation of Moreno and former Chicago Ald. Ambrosio Medrano.

In addition, court records show DiFoggio and wife Fran Prado were embroiled in a nasty domestic battle.

Prado said her husband canceled her credit card, threatened to cut her off financially and wanted to boot her from the house, leading her to have divorce papers drawn up earlier this month, court records show.

DiFoggio refused to accept the divorce papers and instead sold a pricey pleasure boat co-owned by the couple without Prado’s consent. He also made her fork over her wedding ring before giving her $1,500 in spending money.

The trouble reached a boiling point on Saturday, when a spat about the boat sale drew police to their Bridgeport mansion.

Prado said DiFoggio became aggressive and pushed her, records show. But it was DiFoggio who called the cops, alleging Prado was holding a butcher knife to his throat and threatening to “poison his ice cream."

Saturday’s incident — not the first time Prado told authorities her husband had made false allegations to police about her, records show — culminated in Prado asking a judge for an order of protection. It was granted Monday.

“All I wanted was for him to accept service of our divorce papers so we could both move on with our lives,” Prado said in court documents.

Marc Barnett, DiFoggio's defense attorney, said he got word of the death Wednesday morning. He had not spoken with DiFoggio in several weeks.

"I'm shocked, and I'm a little bit surprised," Barnett said. "If it's true, I'm sorry it happened."

Barnett said he had no details of the apparent shooting. "I have no facts," he said.

Moreno's attorney, Richard Kling, said he had not heard of the death until he was reached by a reporter.

"Obviously, Mr. DiFoggio was a troubled individual," said Kling.

Moreno and Medrano were hit with federal charges July 2012. Medrano pleaded guilty to wire fraud in September. It was the third time he was convicted of corruption.

Moreno pleaded guilty to conspiracy to commit extortion. He has a sentencing hearing in January, Kling said.

Reached by phone, Medrano told DNAinfo Chicago he learned of DiFoggio's death Wednesday and "it hit me hard."

"Nobody deserves that. I didn't think I would, but I'm taking it pretty badly," Medrano said. "I feel really badly for him and his family. It's something I don't wish on anyone."

Cicero town spokesman Ray Hanania said town president Larry Dominick "wouldn’t have any comment” on DiFoggio’s death and chided media outlets for trying to “drag us into that story” involving Medrano’s ties with the village.

After DiFoggio was outed as an informant for the feds, he was shunned in his tight-knit Italian-American neighborhood, sources said.

"He didn't have too many friends left around. They thought he was this rat. But he was not a bad guy to work for. He always paid you. A lot of guys in this neighborhood, you'll agree to do a job for $10,000, and when it comes time to pay, they wanna give you eight. He wasn't like that," said one business associate who declined to be named.

Perhaps the most devastating severed tie in the neighborhood stemmed from DiFoggio's exile from the nearby Old Neighborhood Italian American Club, an organization at 3031 S. Shield Ave. co-founded by DiFoggio’s father, Michael “The Blaster” DiFoggio, and mobster Angelo “The Hook” LaPietra.

A representative at the club, which was buzzing with activity on Wednesday, laughed before shutting the door on a reporter seeking comment.

Since 2011, DiFoggio had been trying to sell his Bridgeport home, an 8,400-square-foot mansion in the 3700 block of South Normal Avenue with two kitchens, a home theater and retractable roof over an indoor pool, according to Chicago Real Estate Daily.

The home remains on the market for $1.5 million. Guests who gathered there Wednesday did not answer the door.

Early Wednesday, police remained on the scene outside the plumbing shop, tucked in a residential Armour Square neighborhood in the shadows of U.S. Cellular Field.

Employees at the shop declined to comment.