CHICAGO (CBS) — It’s an October Surprise for Democratic candidate for governor J.B. Pritzker. A leaked confidential report from the Cook County inspector general found Pritzker engaged in a “scheme to defraud” taxpayers, by using a loophole to avoid paying more than $330,000 in property taxes on a Gold Coast mansion.

The Chicago Sun-Times and CapitolFax.com report the inspector general recommended Cook County try to recover more than $330,000 in property tax breaks Pritzker received by removing toilets to have the mansion declared uninhabitable.

“The County ultimately fell victim to a scheme to defraud, executed in part through the use of affidavits, and which resulted in the property owner ultimately receiving property tax refunds totaling $132,747.18 for the years 2012, 2013 and 2014, as well as additional tax savings of $198,684.85 for the years 2015 and 2016,” Inspector General Patrick Blanchard stated in a confidential memo obtained by CapitolFax.

Pritzker, however, insisted he obtained property tax breaks through a routine appeal process, and followed all the rules.

“There are 50,000 people in Cook County every year that seek to have a property tax reassessment, and the majority of those people receive that reassessment. That tells you something about the major flaws in the system,” Pritzker said at an unrelated event Monday afternoon. “I’m telling you that we sought a reassessment like other people do. We went through the process that other people do, and there are clearly flaws in the system that people go through, but we sought it with all the rules in place. We knew what the rules were. We followed the rules.”

Rauner’s campaign quickly denounced Pritzker in a statement Monday afternoon.

“This Inspector General report proves what we knew all along – JB Pritzker is a fraud. From the very beginning, Pritzker was devising a corrupt scheme to defraud Illinois taxpayers by ripping toilets out of his mansion. This wasn’t a standard appeal as Pritzker claimed. Instead, he lied to voters. It’s clear from Pritzker’s repeated use of fraudulent tax dodging that he doesn’t have the character and integrity to be governor,” a Pritzker campaign spokesperson said in an email.

The Rauner campaign has released several attack ads accusing Pritzker of corruption, focusing on the tax breaks he received at that mansion after toilets were removed.