When an anonymous letter alleged “positive proof” that cheating had occurred during a 2011 sergeant’s exam for the Bal Harbour Police Department, Chief Thomas Hunker called an “all hands” meeting of the 30-member force and induced every officer present to provide a DNA cheek swab — so he could unmask the unnamed author.

And when two condo dwellers, one a prominent former banker, went to court over a shoving match in the lobby of the Balmoral on Collins Avenue, Hunker called the judge in an effort to influence the outcome.

A hardnosed, decorated South Florida cop who took charge of the Bal Harbour Police Department 10 years ago, Hunker was used to doing things his way — until he butted heads with the U.S. Justice Department last year.

That drawn-out battle is expected to cost Hunker his job, possibly as early as Thursday.

The Justice Department alleges that Bal Harbour police, under Hunker’s direction, mishandled millions received under a federal forfeiture program. The money, totaling $7.3 million over three years, was generated by village police partnering with federal agencies to investigate drug dealers and money launderers far outside the boundaries of Bal Harbour, a relatively crime-free oceanside town of about 2,500.

When cash was seized, participating agencies got a cut of the loot.

But Bal Harbour has been suspended from the program, and the feds have demanded the village return more than $4 million.

Justice Department investigators say Bal Harbour misspent that money on unjustified overtime and lavish travel, and improper payments to confidential informants. The money also went to cover salaries and benefits for two undercover investigators, and to purchase expensive toys: $100,000 for a police power boat; $225,000 for a sleek surveillance truck.

Suspended with pay since December, the 61-year-old Hunker is now negotiating a severance with Bal Harbour, said his attorney, Richard Sharpstein.

Brash and outspoken, Hunker blames the federal investigation on professional jealousy rooted in his well-established success bringing millions in forfeited cash back to little Bal Harbour.

Now, Hunker is trapped in a no-man’s land: under investigation, and the subject of allegations of misconduct contained in a scathing 12-page report released by the Justice Department’s Office of Inspector General.

Sharpstein called the allegations “innuendo” and “a witch hunt to destroy Tom Hunker completely, unnecessarily.’’

Although no one has accused Hunker of pocketing money, Justice Department investigators say he interfered with arrests and prosecutions, accepted gifts from individuals who could have benefited from his position, and conducted unauthorized checks of criminal databases for people who did not have access to those systems.

Sources familiar with the investigation have grumbled that Bal Harbour cops were fixated on seizing cash to the detriment of the broader goal of breaking up large criminal networks by making arrests and indicting suspects. The federal report noted that Bal Harbour, in its years in the program, never made a single arrest.

In addition to alleging that village police inflated their overtime and racked up lavish expenses, the Justice Department report seemed to go out of its way to slam Hunker.

Investigators said he allowed a drunk friend — a civilian — to drive a police cruiser on the beach; got his wife a “deal” on a Jeep from an auto dealership that did business with the department; and that he hired the son of another friend after the aspiring lawman had washed out at the police academy by, among other transgressions, cheating on a first-aid test.