A federal grand jury looking into Ald. Carrie Austin’s purchase of a new home has also subpoenaed records regarding businesses connected to a family of suburban entrepreneurs whose companies have been paid more than $100 million on City Hall deals in the past 17 years.

All but one of the companies are owned by Lemont businessman Boris Nitchoff, his sons Alex Nitchoff and Constantino Nitchoff and his granddaughter Lauren Nitchoff. The other company is owned by Antonia Tienda, who city records show formerly worked as a project manager for one of the Nitchoff companies.

What their relationship is to Austin isn’t clear. Campaign records don’t show any contributions from them.

But, in September 2016, the longtime South Side alderman got her city council colleagues to approve a resolution to rename a two-block stretch of South Glenroy Avenue between West 105th and West 107th as South Nitchoff Avenue — though the street signs were never changed to reflect that.

Two months later, Austin sponsored a city council tribute to Constantino Nitchoff’s son, a 17-year-old Lemont High School student who’d died.

Austin’s ward office was raided by the FBI on June 19 as part of a grand jury investigation.

The grand jury issued a subpoena seeking items related to “the construction, purchase, financing, rental, or ownership of, and/or work on” the $236,000 home Austin bought in the 12200 block of South Laflin Street last October with a $231,000 loan guaranteed by the federal government.

The subpoena also named five Nitchoff businesses: Mako Properties, Koal Enterprises, Oakk Construction, 995 LLC and Drop Box Inc. It also named Tienda’s Maxwell Services, which frequently works with the Nitchoffs on city contracts.

No one has been charged with any crime in the ongoing federal investigation.

The U.S. attorney’s office wouldn’t comment. The Nitchoffs, Austin and her lawyers didn’t respond to messages or wouldn’t comment.

Since 2002, City Hall has paid the Nitchoff and Tienda companies $100,219,363 for projects that have included soundproofing homes near O’Hare Airport and Midway Airport and rehabbing or replacing porches and roofs for low-income homeowners across the city.

Boris Nitchoff runs Mako Properties in Summit, which buys delinquent property taxes, collecting interest if the homeowner pays up.

Constantino Nitchoff is president of Koal Enterprises, which shares an address with Mako.

Alex Nitchoff is president of Oakk Construction next door. His daughter Lauren Nitchoff owns Drop Box Inc., which she told City Hall she bought from her father. She also said she previously worked for her father’s and grandfather’s companies.

Both sons subcontract work to Tienda’s Maxwell Services, which City Hall has certified as being owned and operated by a Hispanic woman, allowing the Nitchoffs to meet city contracting requirements. She also has gotten city contracts and hired the Nitchoffs as subcontractors. Before starting Maxwell Services in 2001, Tienda worked for Oakk, according to the resume she filed with City Hall.

City records show that since 2002, under former mayors Richard M. Daley and Rahm Emanuel:

• Oakk Construction landed 20 city contracts paying a total of $63.6 million. Five of those contracts were for soundproofing homes around Midway and O’Hare. The bulk of the remaining work involved installation of roofs, porches and other repairs on low-income homes.

• Koal Enterprises got six city contracts totaling $10.9 million, primarily for repairing and replacing furnaces and weatherizing homes for low-income owners.

• Maxwell Services got seven city contracts, paying $25.7 million, for work similar to the Oakk and Koal contracts.

City Hall has released documents showing homeowners have complained about the work done by the Nitchoff and Tienda companies — including one who said the work wasn’t done at all.

The companies also have done work for the Chicago Park District, the Chicago Housing Authority and CEDA, a private agency that serves low-income Cook County residents.

A staff roster on Oakk’s website listed Cindi Degnan, who is the wife of Cook County Circuit Judge Daniel Degnan and daughter-in-law of ex-Daley adviser and former state Sen. Tim Degnan, as doing “administrator/accounting” work.

She wouldn’t comment, saying, “I don’t want to answer any of your questions.”

Her husband also wouldn’t comment.

Boris Nitchoff also heads 105th & Vincennes/Chicago LLC, which took over a residential development in December 2014 in the 105th and Vincennes tax-increment-financing district in Austin’s ward from two other developers, former pro football player Patrick Terrell, who played for several NFL teams, and his partner John Mayher Jr.

The $46 million Renaissance at Beverly Ridge development called for 250 single-family homes on 57.8 acres, with the city putting $11.9 million into the project through the TIF district. According to the Austin subpoena, grand jurors also wanted records regarding the development, which includes South Nitchoff Avenue.

Nitchoff family members have been regular campaign contributors over the past two decades, though not to Austin.

Mainly through the businesses they control, the Nitchoffs have given $223,440 to politicians over the past two decades, campaign finance records show. Among them: former Cook County Assessor Joe Berrios and his 31st Ward protege, former Ald. Ray Suarez. The Nitchoffs gave $32,500 to campaign committees they control, most of that to Suarez, who said he didn’t recognize their name.

“Maybe they came to my golf outings,” Suarez said.

Among others they’ve given campaign money: Cook County Board President Toni Preckwinkle, who got $16,000, Ald. Roberto Maldonado (26th), $12,000, and Cook County Commissioner Jeff Tobolski, $10,300.

Maldonado said he met Boris Nitchoff just before the alderman’s late wife Nancy became ill with cancer. He said the elder Nitchoff is a prostate cancer survivor and came to visit them several times in the hospital.

“He’s a gentleman,” Maldonado said. “He’s never asked me for anything.”

Ald. Howard Brookins (21st) said he set up the TIF district at 105th and Vincennes, where the Nitchoffs had taken over development of the Renaissance at Beverly Ridge, a former brownfield site. The project was remapped out of his ward after the last census.

Brookins described Boris Nitchoff as a “grandfatherly” type who likes to tell how he was introduced to the business of tax buying. When he first came to the United States from Macedonia in what was then Yugoslavia, he had little money and didn’t know he had to pay taxes on his home. Someone purchased the delinquent taxes for a bigger payoff once the homeowner could pay up.

Once Boris Nitchoff redeemed the taxes and got his house back, he went into the tax-buying business himself.

Contributing: Mark Brown, Fran Spielman