The brother of Ald. Harry Osterman (48th) has been slapped with a five-day suspension after being accused of being AWOL from his $51.10-an-hour job at Chicago’s Department of Water Management on New Year’s Eve, then allegedly filling out a fraudulent “edit sheet” to preserve his paycheck.

Hoisting engineer Matthew Osterman was supposed to report to the North District Yard to serve as an “extra” on a leak crew repairing water main breaks. But he never showed up for work that day, sources said.

When a supervisor called Matthew Osterman’s home to ask where he was, the alderman’s brother claimed he overslept. He did not hustle into work.

City employees are required to swipe in and out at the beginning and end of the work day. But Matthew Osterman subsequently filled out a so-called “edit sheet” claiming he had been at work Dec. 31.

“They pulled all the records and GPS’d his machine and he never swiped in or out . . . He was never seen here that day. Several people corroborated the story that he never showed up. They never saw him anywhere,” said a source familiar with the investigation.

“The initial call, he answered and said ‘I overslept.’ From there, the person working in the office assumed he was gonna come in. But he never came in . . . Someone called and tipped them off that Mr. Osterman never even came to the yard. Never showed up physically. They never saw Mr. Osterman that whole day.”

Edit sheets are supposed to be approved by an employee’s supervisor. They are supposed to be reserved for employees who misplace their badges or forget to sign in or out.

Osterman is accused of filling out a fraudulent edit sheet.

“To get paid for New Year’s Day, he would have to work eight hours before the holiday and eight hours after. By default, you lose the holiday if you don’t work the day before or the day after. And if you don’t have vacation time to cover it, you’re out of luck. You lose two days of pay. It’s an incentive to have people present before and after the holiday,” a co-worker said.

“He was out of vacation time. He didn’t want to lose two days pay. So he submitted a sheet that said he was here when he was not actually present.”

Matthew Osterman could not be reached for comment. Ald. Harry Osterman (48th), Mayor Lori Lightfoot’s Housing Committee chairman, did not return phone calls.

The alderman’s brother was initially slapped with a 10-day suspension. The punishment was reduced to five days after he agreed not to appeal, sources said.

A spokesman for water management, Megan Vidis, refused to discuss Osterman’s suspension, calling it a “personnel matter.”

Marty Durkan, business manager for Operating Engineers Local 150, was tight-lipped.

“I can confirm that, following a routine hearing, Mr. Osterman received disciplinary action,” Durkan wrote in a text message to the Chicago Sun-Times.

“I have an obligation to protect his privacy and have no additional information to offer.”

It’s not the first time an alderman’s brother has been at the center of a scandal in the Department of Water Management.

Three years ago, a shake-up triggered by racist, sexist and homophobic emails swept out Water Management Commissioner Barrett Murphy and his top deputies William Bresnahan and Paul Hansen, brother of former Ald. Bernard Hansen (44th).

Inspector General Joe Ferguson stumbled upon the hate-filled emails while investigating allegations Hansen was using his city email account to sell guns.

In a follow-up report, Ferguson said a high-ranking deputy — whom sources identified as Hansen — called African Americans “wild animals” and sent an email with the subject line “Chicago Safari Tickets” to multiple high-ranking Water Management colleagues.

Veteran City Hall insider Randy Conner, who is African American, replaced Murphy and was given carte blanche to clean house.

Allegations of payroll fraud are also nothing new to a Department of Water Management at the center of the Hired Truck and city hiring scandals.

In 2005, nine clout-heavy employees — including the brother-in-law of County Commissioner John Daley — resigned after being accused of falsifying attendance records over a two-month period and possibly longer.

Daley’s brother-in-law John Briatta, Water Management’s $94,827-a-year chief equipment dispatcher, and eight others were assigned to what was known as the “leak desk” at the Jardine Water Filtration Plant.

The cushy assignment of answering phones and prioritizing repair requests was long dominated by 11th Ward loyalists. It was transferred to the 311 non-emergency system after the payroll scandal broke, costing then-Water Management Commissioner Rick Rice his job.