But a decision from the state on the accusations is not expected before Election Day, November 8.
"I don't understand why Mr. (Sam) Moore (the executive director of the Kent County GOP) and the Republican Party are interjecting partisan politics in a non-partisan race here in Grand Rapids," Sak told 24 Hour News 8.
Moore claims it's more about the office than the politics.
"How can you be effective as the watchdog for the people when you're not even watching your own expenditures you're making out of your slush fund?" Moore said.
In the complaint with the state, the GOPs Moore claims Sak broke the rules by spending money in his war chest after he was term-limited out of his position in the state House of Representatives. He left after 2008.
Those rules say an office holder that is term-limited can only use campaign funds to cover expenses incurred while in office or during a campaign.
The comptroller's office - for which Sak is running - is the office which audits city expenditures.
The complaint alleges Sak's candidate committee, Friends of Michael Sak, never dissolved after he left office in 2008, "... but in fact, made several expenditures and disbursements after December 1st, 2008 when Mr. Sak no longer served as a state representative."
Sak violated the rules 81 times, the complaint alleges, for expenditures ranging from a $1,200 event called the Sak Shoot Out at the Mines golf course in Grand Rapids, to $4.95 for postage stamps.
Each violation carries a fine of up to $1, 000.
Sak denies violating any fiance law.
"I just don't believe (I have), due to the fact that the Secretary of State for the last two years has not raised any issues with me," he said.
"It's 13 days out (until the election)," he said. "If there was an issue there, why didn't they bring it to my attention two and a half years ago, almost three years ago?"
Even if there were violations, it may be more a matter of missing T's and undotted I's.
The law also says a candidate can keep and spend campaign money the way Sak did as long as they become a candidate for another office and establish another committee.
Sak's met half the requirements as a City Comptroller candidate.
But was it too little, too late?
"He could have established a new campaign committee two years ago," Moore said. "I'm not sure that it was clear two years ago that he was running for an additional office at that point."
And what about those claims of forcing partisan politics in a non-partisan election?
Moore denies the charge, saying the GOP investigates candidates in a number of local races, both partisan and non-partisan.
"We research most non-partisan races," he said. "We research school board races. We receive a lot of phone calls and people want to know the history of the candidates
