Former Legislative Inspector General Faisal Khan on Wednesday set his muckraking sights on his biggest political targets yet: Illinois House Speaker Michael Madigan, D-Chicago, and Madigan’s handpicked Ald. Marty Quinn (13th).

In an investigation that also implicates Mayor Rahm Emanuel, Khan’s “Project Six” accused Quinn of using $24,992 of his 2015 aldermanic expense allowance to purchase an “industrial multi-purpose vehicle” in violation of city rules that expressly forbid the “purchase of a motor vehicle.”

The Polaris brand Brutus HD PTO Deluxe is billed as the “most versatile utility vehicle in its class” according to the manufacturer, because it can be used to “plow and blow snow, move dirt, level surfaces, lift pallets, mow lawns or large fields and sweep sidewalks.”

Quinn’s voucher for the vehicle purchase was initially rejected by the city’s Department of Finance, citing the prohibition on the purchase of motor vehicles.

The original voucher, obtained by Khan and included in his report, shows handwritten notes to that effect, stating, “Prohibited by Municipal Code. Do not pay.”

But in 2015, sometime between April 19 and May 15, the initial rejection of Quinn’s voucher was reversed by the mayor’s office after a flurry of communications between the city and Madigan’s office that included Kevin Quinn, the alderman’s brother, who is a state employee.

The mayor’s office defended the decision by citing a section of the rules that permit “payment of miscellaneous, ordinary and necessary expenses incurred in connection with the performance of an alderman’s official duties.”

That’s not the only questionable expenditure, according to Khan, who departed his inspector general position after being hamstrung, then forced out by the City Council that hired him.

Since 2013, Quinn submitted $52,513 in expense vouchers for a graffiti blaster and related supplies that was advertised for use by constituents throughout Madigan’s legislative district, which takes in other wards and parts of surrounding suburbs.

Equally troubling to Khan is the fact that the graffiti blaster had a sign that read, “State Rep. Madigan and Ald. Quinn service vehicle” with a phone number of the office that the two men share. The blaster was also advertised on the website that Quinn and Madigan share and at least two pieces of literature paid for by Madigan.

Khan said he finds it difficult to see the sign as “anything other than a campaign sign.”

Madigan could not be reached for comment. The mayor’s office had no immediate comment.

Quinn responded to the investigation by claiming that Khan’s “Project Six” is “part and parcel of the Illinois Policy Institute and Bruce Rauner,” who has demonized Madigan.

But the alderman did not deny any of Khan’s findings. In fact, he defended the spending as a service to his constituents.

“Did I purchase a graffiti blaster when I first started, when it was taking upwards of three weeks to remove graffiti in the 13th Ward, to remove graffiti the same day? Yes — as a way to give that money back to my constituents,” said Quinn, who moonlights as a political consultant for Madigan.

“Did I buy a piece of machinery that has the ability to snowplow sidewalks for 400 of my senior citizens? Yes, I did. … Is that a good use of taxpayer dollars? Yes, it is. I’ve utilized taxpayer dollars to deal with constituent requests.”

Quinn did not respond directly when asked about Khan’s allegation that he used city equipment in a district that was not confined to his ward and that he and Madigan put their names on the equipment in, what amounted to “political advertising.”

“Bruce Rauner. Illinois Policy Institute. Enough said,” the alderman said.

“Utilizing taxpayer dollars to remove graffiti, utilizing taxpayer dollars to remove snow for seniors. Utilizing taxpayer dollars to do extra garbage carts? Yeah. That’s a real good use of taxpayer dollars. Everything else is politics.”

Khan strongly disagreed. To him, the investigation “shows how far Chicago is from truthful and corruption-free governance” and the abuses made possible by allowing aldermen to submit handwritten vouchers for their expenses.

“What is troubling about this investigation is not just the illegal spending of tax dollars by the alderman, but the blatant disregard for the law by the mayor’s office and the cavalier regard for ethics rules by both Ald. Quinn and Speaker Madigan,” Khan was quoted as saying in a press release that accompanied the investigation.

“When the law says an alderman cannot buy a vehicle with taxpayer dollars or put political signs on city property — regardless of their intent — they are required to follow the law. No one, including the mayor or his staff, has veto power. … Illegal actions compounded by collaboration by high-ranking political officials is unacceptable.”