City Treasurer Stephanie Neely’s M-plated cop car and officer assigned to her security detail was spotted outside a downtown office building Thursday — where it sat, for hours — before finally zipping away.

Neely apparently went out the back, not wanting to talk about all that overtime being generated by her personal police detail.

FOX Chicago News and the Better Government Association followed Neely several times this month.

Cameras caught her getting dropped off at home 6:30 a.m. on a Friday, after what looks like a trip to the gym, the officer hauling in Neely’s garbage can on a snowy morning, and the biggest surprise of all: Neely’s son getting into the unmarked squad car all alone for a police-chauffeured drive presumably to school.

This is what Neely told us when FOX Chicago and the BGA broke the story last week.

“Detail came with my job,” Neely said. “It’s how I execute my duties as treasurer. His day starts when my day starts.”

Taxpayers are paying for a lot of police overtime, and thanks to records obtained through the Freedom of Information Act, news investigators now know exactly how long those days are.

The FOIA records show Neely’s primary bodyguard received more than $7,000 in overtime in 2009, $19,000 in 2010 and has already topped $23,000 through Dec. 1 of this year.

The officer’s base salary is $95,000 a year. With overtime, he’s nearly making as much as the politician he’s assigned to drive around.

“These are not chauffeurs, these are not valets, these are not errand boys,” the BGA’s Andy Shaw said. “These are trained police officers who should be protecting regular citizens from street crime in dangerous neighborhoods.”

After the joint investigation aired last week, it hit websites like Second City Cop, Chicagoist and The Huffington Post.

Users posted hundred of comments in response to the story, questioning the reasoning behind Neely’s security detail, defending the Chicago treasurer and saying that there are civilian workers in her office that could do the same job as the officer.

When asked if she really does need a police officer to perform these tasks, Neely dismissed the question, and said that issue could be discussed at a later time.

That was a week ago.

The only sound news investigators heard from Treasurer Neely Thursday was her police car roaring away.